Merge pull request '§22 S6 (last item): spec pass for per-type surfaces (§22.4a items 1 & 3)' (#25) from spec/s7-per-type-surfaces into main

The per-type frontmatter schemas (item 1) and type-specific surfaces (item 3:
specification release-planning; bdd scenario/coverage views) were flagged at
v0.45.0 as wanting a discovery/spec pass first (they lacked BDD scenarios in
Part C). This is that pass — a design doc specifying the schemas, the surfaces,
their data model / API / frontend shape, BDD-style acceptance scenarios, and a
three-slice delivery plan (S7a schemas, S7b releases, S7c bdd surfaces), all
additive and engine-preserving per §22.4a. Doc-only; no code, no version bump.

- docs/design/2026-06-06-per-type-surfaces.md — the new spec pass.
- three-tier design doc S6 bullet: forward-pointer + S6 shipped/spec'd status.

Leaves implementation to the S7a–S7c coding slices; S7a (schemas) is unblocked,
S7b/S7c carry open product questions for the operator/discovery to settle.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

.dockerignore

@@ -0,0 +1,15 @@
+# Keep the preview build context lean + reproducible.
+.git
+.gitea
+**/__pycache__/
+**/*.pyc
+backend/.venv/
+backend/data/
+frontend/node_modules/
+frontend/dist/
+e2e/
+mockups/
+docs/
+*.md
+!VERSION
+.pytest_cache/

.gitignore

@@ -26,3 +26,4 @@ data/
 
 # Claude Code (per-machine settings only; shared config under .claude/ is committed)
 .claude/settings.local.json
+.superpowers/

CLAUDE.md

@@ -1,3 +1,5 @@
+@~/.claude/wiggleverse.md
+
 # Working in rfc-app
 
 This is the framework — the software that hosts an RFC standardization

DOCS.md

@@ -39,23 +39,44 @@ thread. Every write affordance is replaced with a sign-in prompt.
 
 ## Signing in
 
-While the framework is in private beta, only invited email addresses
-can complete sign-in. If your email is on the allowlist, the
-"Sign in" button in the header completes the flow and lands you on
-the catalog with full read and write access. If your email is not on
-the allowlist, you'll be sent to a short "pending" page explaining
-the gate.
+Anyone can start the sign-in flow with their own email address — there
+is no invite-only allowlist. Sign-in is passwordless:
 
-Once you have an account, you're a **contributor** by default — the
-role that grants every write affordance the app exposes, scoped by
-the per-RFC and per-branch rules described below.
+1. **Enter your email.** If the deployment has human verification
+   enabled (a Cloudflare Turnstile challenge), you complete it here.
+2. **Enter the one-time code.** The app emails you a short numeric
+   code; entering it signs you in. Codes expire after a few minutes,
+   and repeated wrong entries briefly lock the email.
+3. **Set a passcode (optional).** After your first code sign-in you
+   can set a passcode. On later visits you sign in with email +
+   passcode, with the one-time code as the forgot-passcode fallback.
+4. **Trust this device (optional).** You can mark a device trusted for
+   30 days to skip the code/passcode step on it. Trusted devices are
+   listed in your settings and can be revoked individually or all at
+   once.
+
+### Getting write access
+
+Signing in gives you an account, but write access is gated. The first
+time you sign in you're asked for your first name, last name, and a
+short note on why you'd like access; you then land on a "request in
+review" page. While your account is **pending**, you can read
+everything an anonymous visitor can but cannot write — no chat,
+propose, branch, PR, or discussion post. Once an admin **grants** your
+account you become a **contributor**, the role that carries every
+write affordance the app exposes, scoped by the per-RFC and per-branch
+rules described below.
+
+An admin can also create your account ahead of time and email you an
+invite link. Clicking it claims the account and signs you in with the
+role the admin assigned, skipping the one-time-code step.
 
 ---
 
 ## Proposing a new RFC
 
 A new RFC begins as a proposal. The "+ Propose new RFC" button at
-the bottom of the catalog opens a small modal that collects four
+the bottom of the catalog opens a small modal that collects five
 things:
 
 - **Title.** The word, concept, or topic this RFC would define.
@@ -65,8 +86,13 @@ things:
   inline.
 - **Pitch.** One or two paragraphs answering *why this RFC is
   needed*. This becomes the body of the entry.
-- **Tags.** Optional. The AI suggests tags from the pitch; you can
-  accept, dismiss, or type your own.
+- **Use case.** Optional. *What will you be using this RFC for?* —
+  the concrete application driving the proposal, as distinct from the
+  abstract case for it. Leaving it blank is fine.
+- **Tags.** Optional. If the deployment has AI tag suggestion
+  enabled, suggested tags appear as you fill the form (with an inline
+  note that the text you've entered is sent to the model that
+  generates them); you can accept, dismiss, or type your own.
 
 Submitting the modal does one concrete thing: it opens a pull
 request against the framework's meta repository, adding one new
@@ -167,6 +193,51 @@ either requires a contributor account.
 
 ---
 
+## Invitations, cross-references, and contribution requests
+
+Three connected surfaces help the right people find and join the
+right RFC.
+
+### Owner invitations
+
+An RFC's owner (or an app-wide admin or owner) can invite a specific
+person to that RFC from the "Invitations" control in the RFC header.
+The invite names an email and a role for *this RFC*:
+
+- **contributor** — can open PRs and join the discussion;
+- **discussant** — can join the discussion only.
+
+The invitee gets an email with an accept link; accepting adds them as
+a collaborator on that RFC. The invitations panel lists every invite
+with its status (pending / accepted / expired / revoked); pending
+invites can be revoked. An invitation is per-RFC — it does not change
+the invitee's app-wide role, and it cannot lift the pending gate: the
+invitee still needs a granted account to write.
+
+### RFC cross-links in PRs and comments
+
+When a PR description or a comment mentions an existing active RFC —
+by its ID, its multi-word title, or its slug — the framework renders
+that mention as a link to the RFC. The matching is conservative by
+design (single common words are never auto-linked), and the links are
+computed at read time, so nothing is rewritten in what you typed.
+
+### "Create" and "ask to contribute" offers
+
+The same scan surfaces two affordances inline:
+
+- If a term looks like it should have an RFC but none exists yet, a
+  reader who has create rights sees a **"create RFC for '<term>'"**
+  link that opens the propose modal with the title pre-filled.
+- If a term matches a *pending* RFC (a super-draft someone already
+  owns), a signed-in reader sees an **"ask to contribute"** offer
+  naming the owner. It opens a short request form — who you are, why
+  you're asking, and optionally what you'd use the RFC for. The
+  request lands in the owner's inbox; the owner can **accept** (which
+  sends you an owner invitation) or **decline** (which notifies you).
+
+---
+
 ## Working on a branch
 
 Contribute mode flips one branch into edit-enabled. The centre
@@ -505,6 +576,14 @@ Each role is a strict superset of the one below it.
    entirely. The framework names a single "owner zero" at
    bootstrap.
 
+Between anonymous and contributor sits one transient state:
+**pending**. A freshly signed-in account that hasn't been granted
+access yet (see [Signing in](#signing-in)) reads everything an
+anonymous visitor can, but no write affordance unlocks until an admin
+grants it. Granting promotes the account to contributor; an admin can
+also revoke a granted account back to a no-write state. These
+transitions are recorded in the `permission_events` log.
+
 The practical difference between admin and owner is narrow but
 load-bearing: admin is the operational tier — it does the day-to-
 day moderation and stewardship work; owner is the tier that
@@ -594,6 +673,20 @@ review.
 
 ---
 
+## Privacy and cookies
+
+A consent banner appears on your first visit and lets you choose
+which cookie categories to allow — essential always, with analytics
+and other categories opt-in. The choice is remembered and can be
+changed any time from the privacy/cookies controls in settings.
+
+Analytics only load if you opt in: the framework defers the analytics
+SDK behind your consent, so declining means it is never initialized.
+The `/privacy` and `/cookies` pages describe what's collected and
+why; a deployment can point those pages at its own fuller policy.
+
+---
+
 ## Where to learn more
 
 - The framework's *why* lives in [the philosophy

Dockerfile

@@ -0,0 +1,62 @@
+# rfc-app container image — the Cloud Run keystone for per-PR preview
+# environments (flotilla SPEC §15). NOT used by production: prod still deploys
+# via the pin-based on-VM gesture (flotilla §8). This image exists so flotilla
+# `preview up --pr=N` can build a PR's tree and run it as an ephemeral,
+# scale-to-zero Cloud Run service with a SEEDED SYNTHETIC database and ZERO real
+# secrets (test-secret env only — flotilla §15 / §3 invariant 1).
+#
+# Single container, single port: nginx serves the built SPA on $PORT (Cloud Run
+# injects it) and reverse-proxies /api/ + /auth/ to a single-process uvicorn on
+# 127.0.0.1:8000 — mirroring the prod nginx + systemd split
+# (deploy/nginx/ohm.wiggleverse.org.conf, deploy/systemd/rfc-app.service), so a
+# preview behaves like prod minus the secrets. Single uvicorn process + single
+# SQLite file, per §4.2 (never scale workers).
+#
+# Build context is the repo root:  docker build -t <image> .
+
+# ---- stage 1: build the Vite SPA -------------------------------------------
+FROM node:20-slim AS web
+WORKDIR /app/frontend
+COPY frontend/package.json frontend/package-lock.json ./
+RUN npm ci
+COPY frontend/ ./
+# VITE_* values are baked into the bundle at build time (intentionally public —
+# §8 phase-5 note). VITE_APP_NAME is REQUIRED by vite.config.js (the framework
+# ships no default — each deployment names itself); previews self-name. Turnstile
+# uses Cloudflare's always-pass test SITE key so the widget renders + auto-passes.
+ARG VITE_APP_NAME="RFC App (preview)"
+ARG VITE_TURNSTILE_SITE_KEY=1x00000000000000000000AA
+ARG VITE_AMPLITUDE_API_KEY=
+RUN VITE_APP_NAME="$VITE_APP_NAME" \
+    VITE_TURNSTILE_SITE_KEY="$VITE_TURNSTILE_SITE_KEY" \
+    VITE_AMPLITUDE_API_KEY="$VITE_AMPLITUDE_API_KEY" \
+    npm run build
+
+# ---- stage 2: runtime (backend + nginx) ------------------------------------
+FROM python:3.12-slim AS runtime
+RUN apt-get update \
+    && apt-get install -y --no-install-recommends nginx gettext-base sqlite3 \
+    && rm -rf /var/lib/apt/lists/*
+
+WORKDIR /opt/rfc-app
+
+# Backend deps first for layer caching.
+COPY backend/requirements.txt backend/requirements.txt
+RUN pip install --no-cache-dir -r backend/requirements.txt
+
+COPY backend/ backend/
+COPY deploy/preview/ deploy/preview/
+# health.py reads VERSION at parents[2] (== /opt/rfc-app/VERSION).
+COPY VERSION ./
+COPY --from=web /app/frontend/dist/ frontend/dist/
+
+RUN chmod +x deploy/preview/entrypoint.sh
+
+# Cloud Run injects $PORT (default 8080); the entrypoint renders nginx against
+# it. The synthetic preview DB lives on the container's ephemeral filesystem and
+# dies with the instance (zero create/seed/drop lifecycle — §15).
+ENV PORT=8080 \
+    DATABASE_PATH=/opt/rfc-app/backend/data/rfc-app.db
+EXPOSE 8080
+
+ENTRYPOINT ["deploy/preview/entrypoint.sh"]

Makefile

@@ -0,0 +1,19 @@
+.PHONY: tier1-up tier1-down tier1-logs fe-unit e2e e2e-install
+
+tier1-up:
+	docker compose -f testing/docker-compose.yml up --build -d
+
+tier1-down:
+	docker compose -f testing/docker-compose.yml down -v
+
+tier1-logs:
+	docker compose -f testing/docker-compose.yml logs -f
+
+fe-unit:
+	cd frontend && npm run test:run
+
+e2e-install:
+	cd e2e && npm ci && npx playwright install chromium
+
+e2e:
+	cd e2e && BASE_URL=$${BASE_URL:-http://localhost:8080} MAILSINK_URL=$${MAILSINK_URL:-http://localhost:8025} npm run e2e

VERSION

@@ -1 +1 @@
-0.26.0
+0.46.0

backend/.env.example

@@ -9,10 +9,18 @@ GITEA_URL=http://localhost:3000
 GITEA_BOT_USER=rfc-bot
 GITEA_BOT_TOKEN=
 
-# The Gitea org or user that owns the meta repo and every RFC repo
-# the bot will create on graduation.
+# The Gitea org or user that owns every RFC repo the bot will create on
+# graduation.
 GITEA_ORG=wiggleverse
-META_REPO=meta
+
+# §22.2 — the project registry repo (REQUIRED). The framework reads
+# `projects.yaml` at its root to learn which projects exist. The repo name is
+# the deployment's choice; the app fails to start if this is unset.
+REGISTRY_REPO=registry
+# §22.13 — optional id for the bootstrap/default project. Reserved for the
+# Plan B re-stamp; leave unset in Plan A (the default project id stays
+# `default`). When set, it must match an `id` in projects.yaml.
+# DEFAULT_PROJECT_ID=ohm
 
 # --- OAuth (Gitea) ---
 # In Gitea: Site Administration → Applications → Add OAuth2 Application.

backend/app/api.py

@@ -21,12 +21,19 @@ from pydantic import BaseModel, Field
 from . import (
     api_admin,
     api_branches,
+    api_collections,
+    api_contributions,
+    api_deployment,
     api_discussion,
     api_graduation,
     api_invitations,
+    api_join_requests,
+    api_memberships,
     api_notifications,
     api_prs,
     auth,
+    collections as collections_mod,
+    projects as projects_mod,
     db,
     device_trust as device_trust_mod,
     docs as docs_mod,
@@ -141,6 +148,21 @@ def make_router(
     # invited users keep read access but cannot write (v0.6.0
     # contract extended to per-RFC scope).
     router.include_router(api_invitations.make_router())
+    # v0.29.0 (roadmap item #28 Part 3): offer-to-contribute-to-a-pending
+    # (super-draft) RFC. Reuses the #12 invite flow (api_invitations above)
+    # on accept; lands the request + owner notifications via §15 notify.
+    router.include_router(api_contributions.make_router())
+    # §22.9/§22.10 (M3): runtime deployment + per-project config (replaces
+    # VITE_APP_NAME) + the old-URL 308 redirects.
+    router.include_router(api_deployment.make_router(config, gitea, bot))
+    router.include_router(api_collections.make_router(config, gitea, bot))
+    # §22 S4 (C.2): the scope-role invitation surface — Owners grant
+    # {owner, contributor} at project/collection scope to existing accounts.
+    router.include_router(api_memberships.make_router())
+    # §22.8 S6: request-to-join + the cross-collection inbox — a user asks into a
+    # scope (naming a role); the scope's Owners across the subtree accept (writing
+    # the membership row) or decline.
+    router.include_router(api_join_requests.make_router())
 
     # ---------------------------------------------------------------
     # §17: /api/health — unauthenticated post-flight probe.
@@ -602,25 +624,40 @@ def make_router(
     # ---------------------------------------------------------------
 
     @router.get("/api/rfcs")
-    async def list_rfcs(request: Request) -> dict[str, Any]:
+    async def list_rfcs(request: Request, unreviewed: str | None = None) -> dict[str, Any]:
         """§7's left pane data.
 
         The chip-filter / sort / search combinatorics live on the
         client — the server returns the full set and lets the chips
         narrow it. The set is small (hundreds, not thousands) for the
         foreseeable future, so paginating here would buy nothing.
+
+        §22.4c: pass `?unreviewed=true` to narrow to active entries
+        still awaiting owner review.
         """
         viewer = auth.current_user(request)
         viewer_id = viewer.user_id if viewer else None
+        # §22.5: a gated project's entries never surface in a non-member's
+        # catalog. For the single public default project this is the full set.
+        visible = auth.visible_project_ids(viewer)
+        if not visible:
+            return {"items": []}
+        placeholders = ",".join("?" for _ in visible)
+        params = list(visible)
+        unreviewed_clause = ""
+        if unreviewed is not None and unreviewed.lower() in ("1", "true", "yes"):
+            unreviewed_clause = " AND unreviewed = 1 AND state = 'active'"
         rows = db.conn().execute(
-            """
-            SELECT slug, title, state, rfc_id, repo,
-                   owners_json, arbiters_json, tags_json,
-                   last_main_commit_at, last_entry_commit_at, updated_at
-              FROM cached_rfcs
-             WHERE state IN ('super-draft', 'active')
-             ORDER BY COALESCE(last_main_commit_at, last_entry_commit_at) DESC
-            """
+            f"""
+            SELECT r.slug, r.title, r.state, r.rfc_id, r.repo,
+                   r.owners_json, r.arbiters_json, r.tags_json,
+                   r.last_main_commit_at, r.last_entry_commit_at, r.updated_at
+              FROM cached_rfcs r JOIN collections c ON c.id = r.collection_id
+             WHERE r.state IN ('super-draft', 'active')
+               AND c.project_id IN ({placeholders}){unreviewed_clause}
+             ORDER BY COALESCE(r.last_main_commit_at, r.last_entry_commit_at) DESC
+            """,
+            params,
         ).fetchall()
 
         starred = set()
@@ -652,12 +689,21 @@ def make_router(
         return {"items": items}
 
     @router.get("/api/rfcs/{slug}")
-    async def get_rfc(slug: str) -> dict[str, Any]:
+    async def get_rfc(slug: str, request: Request) -> dict[str, Any]:
         row = db.conn().execute(
             "SELECT * FROM cached_rfcs WHERE slug = ?", (slug,)
         ).fetchone()
         if row is None:
             raise HTTPException(404, "Not found")
+        viewer = auth.current_user(request)
+        # §22.5 visibility gate (subtractive, §22.7): a gated project's entries
+        # 404 to non-members. Recover the project via the entry's collection.
+        auth.require_project_readable(viewer, auth.project_of_rfc(slug))
+        # §13.7: a retired entry is removed from every browsing surface. The
+        # sole exception is a site owner, so the un-retire affordance has
+        # somewhere to live; everyone else gets a plain 404.
+        if row["state"] == "retired" and (viewer is None or viewer.role != "owner"):
+            raise HTTPException(404, "Not found")
         payload = _serialize_rfc(row)
         # Roadmap #26: surface the optional propose-time use case on the
         # RFC view. The idea PR closes on merge, but the canonical row in
@@ -674,6 +720,166 @@ def make_router(
         payload["proposed_use_case"] = uc["use_case"] if uc else None
         return payload
 
+    # ---------------------------------------------------------------
+    # §22.4 (Plan B): per-project RFC serving — the catalog + entry view
+    # scoped to one project, identified by its own slug namespace
+    # (project_id, slug). The unscoped /api/rfcs[/{slug}] above stay as the
+    # default-project compat path; the frontend reads these scoped routes so a
+    # second project's corpus renders under /p/<id>/.
+    # ---------------------------------------------------------------
+
+    def _require_collection_in_project(collection_id: str, project_id: str) -> None:
+        # §22 S2: a collection-scoped route 404s when the collection does not
+        # belong to the project in the path (shape matches an unknown id).
+        if collections_mod.project_of_collection(collection_id) != project_id:
+            raise HTTPException(404, "Not found")
+
+    def _list_rfcs_for_collection(
+        collection_id: str, viewer, unreviewed: str | None
+    ) -> dict[str, Any]:
+        viewer_id = viewer.user_id if viewer else None
+        unreviewed_clause = ""
+        if unreviewed is not None and unreviewed.lower() in ("1", "true", "yes"):
+            unreviewed_clause = " AND unreviewed = 1 AND state = 'active'"
+        rows = db.conn().execute(
+            f"""
+            SELECT slug, title, state, rfc_id, repo,
+                   owners_json, arbiters_json, tags_json,
+                   last_main_commit_at, last_entry_commit_at, updated_at
+              FROM cached_rfcs
+             WHERE state IN ('super-draft', 'active')
+               AND collection_id = ?{unreviewed_clause}
+             ORDER BY COALESCE(last_main_commit_at, last_entry_commit_at) DESC
+            """,
+            (collection_id,),
+        ).fetchall()
+        starred = set()
+        if viewer_id is not None:
+            starred = {
+                r["rfc_slug"]
+                for r in db.conn().execute(
+                    "SELECT rfc_slug FROM stars WHERE user_id = ? AND collection_id = ?",
+                    (viewer_id, collection_id),
+                )
+            }
+        items = [
+            {
+                "slug": r["slug"],
+                "title": r["title"],
+                "state": r["state"],
+                "id": r["rfc_id"],
+                "repo": r["repo"],
+                "owners": json.loads(r["owners_json"] or "[]"),
+                "arbiters": json.loads(r["arbiters_json"] or "[]"),
+                "tags": json.loads(r["tags_json"] or "[]"),
+                "last_active_at": r["last_main_commit_at"] or r["last_entry_commit_at"] or r["updated_at"],
+                "starred_by_me": r["slug"] in starred,
+                "has_open_prs": False,
+            }
+            for r in rows
+        ]
+        return {"items": items}
+
+    def _get_rfc_for_collection(collection_id: str, slug: str, viewer) -> dict[str, Any]:
+        row = db.conn().execute(
+            "SELECT * FROM cached_rfcs WHERE collection_id = ? AND slug = ?",
+            (collection_id, slug),
+        ).fetchone()
+        if row is None:
+            raise HTTPException(404, "Not found")
+        if row["state"] == "retired" and (viewer is None or viewer.role != "owner"):
+            raise HTTPException(404, "Not found")
+        payload = _serialize_rfc(row)
+        uc = db.conn().execute(
+            """
+            SELECT use_case FROM proposed_use_cases
+             WHERE scope = 'rfc' AND rfc_slug = ? AND collection_id = ?
+             ORDER BY id DESC LIMIT 1
+            """,
+            (slug, collection_id),
+        ).fetchone()
+        payload["proposed_use_case"] = uc["use_case"] if uc else None
+        return payload
+
+    @router.get("/api/projects/{project_id}/rfcs")
+    async def list_project_rfcs(
+        project_id: str, request: Request, unreviewed: str | None = None
+    ) -> dict[str, Any]:
+        viewer = auth.current_user(request)
+        # §22.5 read gate: a gated project's catalog 404s to a non-member.
+        auth.require_project_readable(viewer, project_id)
+        # §22 S1: the project-scoped route serves the default collection.
+        collection_id = collections_mod.default_collection_id(project_id)
+        return _list_rfcs_for_collection(collection_id, viewer, unreviewed)
+
+    @router.get("/api/projects/{project_id}/rfcs/{slug}")
+    async def get_project_rfc(project_id: str, slug: str, request: Request) -> dict[str, Any]:
+        viewer = auth.current_user(request)
+        auth.require_project_readable(viewer, project_id)
+        collection_id = collections_mod.default_collection_id(project_id)
+        return _get_rfc_for_collection(collection_id, slug, viewer)
+
+    # §22 S2: collection-scoped serve + propose. The catalog/entry views read
+    # these under /p/<project>/c/<collection>/; the project-scoped routes above
+    # stay as the default-collection compat surface.
+    @router.get("/api/projects/{project_id}/collections/{collection_id}/rfcs")
+    async def list_collection_rfcs(
+        project_id: str, collection_id: str, request: Request,
+        unreviewed: str | None = None,
+    ) -> dict[str, Any]:
+        viewer = auth.current_user(request)
+        auth.require_project_readable(viewer, project_id)
+        _require_collection_in_project(collection_id, project_id)
+        # §22.5 (S3): a hidden/gated collection 404s to a non-scope-role viewer.
+        auth.require_collection_readable(viewer, collection_id)
+        return _list_rfcs_for_collection(collection_id, viewer, unreviewed)
+
+    @router.get("/api/projects/{project_id}/collections/{collection_id}/rfcs/{slug}")
+    async def get_collection_rfc(
+        project_id: str, collection_id: str, slug: str, request: Request
+    ) -> dict[str, Any]:
+        viewer = auth.current_user(request)
+        auth.require_project_readable(viewer, project_id)
+        _require_collection_in_project(collection_id, project_id)
+        auth.require_collection_readable(viewer, collection_id)
+        return _get_rfc_for_collection(collection_id, slug, viewer)
+
+    # ---------------------------------------------------------------
+    # §22.4c: mark-reviewed — clear an active entry's `unreviewed` flag
+    # ---------------------------------------------------------------
+
+    @router.post("/api/projects/{project_id}/rfcs/{slug}/mark-reviewed")
+    async def mark_reviewed(project_id: str, slug: str, request: Request) -> dict[str, Any]:
+        """§22.4c — clear an active entry's `unreviewed` flag. Authority is the
+        §B.2 collection Owner (a collection/project/global Owner or deployment
+        owner/admin reaching the entry's collection)."""
+        viewer = auth.require_user(request)
+        auth.require_project_readable(viewer, project_id)
+        collection_id = collections_mod.default_collection_id(project_id)
+        if not auth.is_collection_superuser(viewer, collection_id):
+            raise HTTPException(403, "Only a collection owner can mark an entry reviewed")
+        row = db.conn().execute(
+            "SELECT state, unreviewed FROM cached_rfcs WHERE slug = ? AND collection_id = ?",
+            (slug, collection_id),
+        ).fetchone()
+        if row is None:
+            raise HTTPException(404, "Not found")
+        if row["state"] != "active" or not row["unreviewed"]:
+            raise HTTPException(409, "Entry is not an unreviewed active entry")
+        try:
+            await bot.mark_entry_reviewed(
+                viewer.as_actor(),
+                org=config.gitea_org,
+                meta_repo=(projects_mod.default_content_repo(config) or ""),
+                slug=slug,
+                reviewed_by=viewer.gitea_login,
+                reviewed_at=entry_mod.today(),
+            )
+        except GiteaError as e:
+            raise HTTPException(502, f"Gitea: {e.detail}")
+        await cache.refresh_meta_repo(config, gitea)
+        return {"ok": True}
+
     # ---------------------------------------------------------------
     # §7.3 / §9.3: pending ideas
     # ---------------------------------------------------------------
@@ -689,14 +895,50 @@ def make_router(
         return row["use_case"] if row else None
 
     @router.get("/api/proposals")
-    async def list_proposals() -> dict[str, Any]:
+    async def list_proposals(request: Request) -> dict[str, Any]:
+        # §22.5: idea PRs in a gated project never surface to non-members.
+        visible = auth.visible_project_ids(auth.current_user(request))
+        if not visible:
+            return {"items": []}
+        placeholders = ",".join("?" for _ in visible)
+        rows = db.conn().execute(
+            f"""
+            SELECT rfc_slug, pr_number, title, description, opened_by, opened_at, state
+              FROM cached_prs
+             WHERE pr_kind = 'idea' AND state = 'open'
+               AND project_id IN ({placeholders})
+             ORDER BY opened_at DESC
+            """,
+            visible,
+        ).fetchall()
+        return {
+            "items": [
+                {
+                    "slug": r["rfc_slug"],
+                    "pr_number": r["pr_number"],
+                    "title": r["title"],
+                    "description": r["description"],
+                    "opened_by": r["opened_by"],
+                    "opened_at": r["opened_at"],
+                    "proposed_use_case": _proposal_use_case(r["pr_number"]),
+                }
+                for r in rows
+            ]
+        }
+
+    @router.get("/api/projects/{project_id}/proposals")
+    async def list_project_proposals(project_id: str, request: Request) -> dict[str, Any]:
+        # §22.4/§22.5: the pending idea-PRs scoped to one project.
+        viewer = auth.current_user(request)
+        auth.require_project_readable(viewer, project_id)
         rows = db.conn().execute(
             """
             SELECT rfc_slug, pr_number, title, description, opened_by, opened_at, state
               FROM cached_prs
-             WHERE pr_kind = 'idea' AND state = 'open'
+             WHERE pr_kind = 'idea' AND state = 'open' AND project_id = ?
              ORDER BY opened_at DESC
-            """
+            """,
+            (project_id,),
         ).fetchall()
         return {
             "items": [
@@ -731,10 +973,12 @@ def make_router(
         ).fetchone()
         if row is None:
             raise HTTPException(404, "Not a proposal PR")
+        # §22.5 visibility gate (subtractive): gated → 404 to non-members.
+        auth.require_project_readable(auth.current_user(request), row["project_id"])
         # Read the proposed entry file from the head branch.
         slug = row["rfc_slug"]
         head = row["head_branch"]
-        result = await gitea.read_file(config.gitea_org, config.meta_repo, f"rfcs/{slug}.md", ref=head)
+        result = await gitea.read_file(config.gitea_org, (projects_mod.default_content_repo(config) or ""), f"rfcs/{slug}.md", ref=head)
         entry_payload: dict[str, Any] | None = None
         if result:
             text, _sha = result
@@ -763,9 +1007,21 @@ def make_router(
     # §9.1: propose a new RFC
     # ---------------------------------------------------------------
 
-    @router.post("/api/rfcs/propose")
-    async def propose_rfc(payload: ProposeBody, request: Request) -> dict[str, Any]:
-        user = auth.require_contributor(request)
+    async def _propose_into_project(project_id: str, payload: ProposeBody, user) -> dict[str, Any]:
+        # Default-collection wrapper (§22 S1/S2): resolve the project's default
+        # collection and delegate. Keeps the project-scoped propose routes intact.
+        return await _propose_into_collection(
+            project_id, collections_mod.default_collection_id(project_id), payload, user
+        )
+
+    async def _propose_into_collection(
+        project_id: str, collection_id: str, payload: ProposeBody, user
+    ) -> dict[str, Any]:
+        # §B.2 (S3): proposing a new entry requires contribute standing in the
+        # *target collection* — the four-layer scope-role union, with the
+        # grandfathered implicit-public baseline on the default collection.
+        if not auth.can_contribute_in_collection(user, collection_id):
+            raise HTTPException(403, "You do not have contribute access to this collection")
         slug = payload.slug.strip().lower()
         if not entry_mod.is_valid_slug(slug):
             raise HTTPException(422, "Slug must be lowercase letters, digits, and dashes")
@@ -775,21 +1031,29 @@ def make_router(
         # on every keystroke, since a concurrent submission could land
         # between dialog-open and submit.
         clash = db.conn().execute(
-            "SELECT 1 FROM cached_rfcs WHERE slug = ?", (slug,)
+            "SELECT 1 FROM cached_rfcs WHERE slug = ? AND collection_id = ?", (slug, collection_id)
         ).fetchone()
         if clash:
             raise HTTPException(409, f"Slug `{slug}` is already taken")
         idea_clash = db.conn().execute(
-            "SELECT 1 FROM cached_prs WHERE pr_kind = 'idea' AND state = 'open' AND rfc_slug = ?",
-            (slug,),
+            "SELECT 1 FROM cached_prs WHERE pr_kind = 'idea' AND state = 'open' "
+            "AND rfc_slug = ? AND project_id = ?",
+            (slug, project_id),
         ).fetchone()
         if idea_clash:
             raise HTTPException(409, f"Slug `{slug}` is already reserved by an open proposal")
 
+        # §22.4b: the target collection's landing state (the per-corpus field
+        # moved down to the collection in migration 029).
+        landing_state = (
+            "active" if collections_mod.collection_initial_state(collection_id) == "active"
+            else "super-draft"
+        )
+
         entry = entry_mod.Entry(
             slug=slug,
             title=payload.title.strip(),
-            state="super-draft",
+            state=landing_state,
             id=None,
             repo=None,
             proposed_by=user.email or user.gitea_login,
@@ -804,6 +1068,7 @@ def make_router(
             arbiters=[],
             tags=[t.strip() for t in payload.tags if t.strip()],
             body=payload.pitch.strip() + "\n",
+            unreviewed=(landing_state == "active"),
         )
         contents = entry_mod.serialize(entry)
         pr_title = f"Propose: {entry.title}"
@@ -814,15 +1079,19 @@ def make_router(
             f"**Topic:** {entry.title}\n\n"
             f"{payload.pitch.strip()}"
         )
+        # §22 S2: write the entry under the target collection's <subfolder>/rfcs.
+        subfolder = collections_mod.subfolder_of(collection_id)
+        rfcs_dir = f"{subfolder}/rfcs" if subfolder else "rfcs"
         try:
             pr = await bot.open_idea_pr(
                 user.as_actor(),
                 org=config.gitea_org,
-                meta_repo=config.meta_repo,
+                meta_repo=(projects_mod.content_repo(project_id) or ""),
                 slug=slug,
                 file_contents=contents,
                 pr_title=pr_title,
                 pr_description=pr_description,
+                rfcs_dir=rfcs_dir,
             )
         except GiteaError as e:
             raise HTTPException(502, f"Gitea: {e.detail}")
@@ -842,19 +1111,48 @@ def make_router(
         if use_case:
             db.conn().execute(
                 """
-                INSERT INTO proposed_use_cases (scope, rfc_slug, pr_number, use_case)
-                VALUES ('rfc', ?, ?, ?)
-                ON CONFLICT(scope, pr_number) DO UPDATE SET use_case = excluded.use_case
+                INSERT INTO proposed_use_cases (scope, rfc_slug, pr_number, use_case, collection_id)
+                VALUES ('rfc', ?, ?, ?, ?)
+                ON CONFLICT(collection_id, scope, pr_number) DO UPDATE SET use_case = excluded.use_case
                 """,
-                (slug, pr["number"], use_case),
+                (slug, pr["number"], use_case, collection_id),
             )
             db.conn().execute(
-                "UPDATE cached_prs SET proposed_use_case = ? WHERE pr_kind = 'idea' AND pr_number = ?",
-                (use_case, pr["number"]),
+                "UPDATE cached_prs SET proposed_use_case = ? WHERE pr_kind = 'idea' AND pr_number = ? AND project_id = ?",
+                (use_case, pr["number"], project_id),
             )
 
         return {"pr_number": pr["number"], "slug": slug}
 
+    @router.post("/api/rfcs/propose")
+    async def propose_rfc(payload: ProposeBody, request: Request) -> dict[str, Any]:
+        # Default-project compat path (pre-multi-project clients).
+        user = auth.require_contributor(request)
+        return await _propose_into_project(projects_mod.resolved_default_id(config), payload, user)
+
+    @router.post("/api/projects/{project_id}/rfcs/propose")
+    async def propose_project_rfc(
+        project_id: str, payload: ProposeBody, request: Request
+    ) -> dict[str, Any]:
+        # §22.4: propose a new entry into a specific project (read-gated first
+        # so a gated project 404s a non-member before the contribute check).
+        user = auth.require_contributor(request)
+        auth.require_project_readable(user, project_id)
+        return await _propose_into_project(project_id, payload, user)
+
+    @router.post("/api/projects/{project_id}/collections/{collection_id}/rfcs/propose")
+    async def propose_collection_rfc(
+        project_id: str, collection_id: str, payload: ProposeBody, request: Request
+    ) -> dict[str, Any]:
+        # §22 S2: propose a new entry into a specific collection of a project.
+        user = auth.require_contributor(request)
+        auth.require_project_readable(user, project_id)
+        _require_collection_in_project(collection_id, project_id)
+        # §22.5 (S3): a hidden/gated collection 404s a non-scope-role viewer
+        # before the contribute check (existence is not revealed).
+        auth.require_collection_readable(user, collection_id)
+        return await _propose_into_collection(project_id, collection_id, payload, user)
+
     # ---------------------------------------------------------------
     # §9.1 Slice 2 (roadmap #27): Claude Haiku tag suggestions as the
     # propose-RFC fields fill in. The modal debounce-posts the partial
@@ -894,7 +1192,7 @@ def make_router(
             await bot.merge_idea_pr(
                 user.as_actor(),
                 org=config.gitea_org,
-                meta_repo=config.meta_repo,
+                meta_repo=(projects_mod.default_content_repo(config) or ""),
                 pr_number=pr_number,
                 slug=row["rfc_slug"],
             )
@@ -914,7 +1212,7 @@ def make_router(
             await bot.decline_idea_pr(
                 user.as_actor(),
                 org=config.gitea_org,
-                meta_repo=config.meta_repo,
+                meta_repo=(projects_mod.default_content_repo(config) or ""),
                 pr_number=pr_number,
                 slug=row["rfc_slug"],
                 comment=body.comment,
@@ -938,7 +1236,7 @@ def make_router(
             await bot.withdraw_idea_pr(
                 user.as_actor(),
                 org=config.gitea_org,
-                meta_repo=config.meta_repo,
+                meta_repo=(projects_mod.default_content_repo(config) or ""),
                 pr_number=pr_number,
                 slug=row["rfc_slug"],
             )
@@ -994,6 +1292,8 @@ def make_router(
         ).fetchone()
         if rfc is None:
             raise HTTPException(404, "RFC not found")
+        # §22.5 visibility gate (subtractive): gated → 404 to non-members.
+        auth.require_project_readable(user, auth.project_of_rfc(slug))
         # §6.7: refuse consent from a user with no registered credentials
         # — a consent without a universe would be inert and the surface
         # should fail loudly rather than silently.

backend/app/api_admin.py

@@ -829,6 +829,57 @@ def make_router(config: Config) -> APIRouter:
                 items_blocked.append(payload)
         return {"ready": items_ready, "blocked": items_blocked}
 
+    # ----- §13.7: retired (soft-deleted) entries — site owners only -----
+
+    @router.get("/api/admin/retired-rfcs")
+    async def retired_rfcs(request: Request) -> dict[str, Any]:
+        # Retired entries are hidden from every browsing surface (§13.7);
+        # this owner-gated list is how a site owner discovers them to
+        # un-retire. Admins do not get this surface — un-retire authority is
+        # site-owner-only, so neither is the list that feeds it.
+        viewer = auth.require_admin(request)
+        if viewer.role != "owner":
+            raise HTTPException(403, "Site owner role required")
+        rows = db.conn().execute(
+            """
+            SELECT slug, title, rfc_id, owners_json, tags_json,
+                   proposed_at, updated_at
+              FROM cached_rfcs
+             WHERE state = 'retired'
+             ORDER BY updated_at DESC
+            """
+        ).fetchall()
+        items = []
+        for r in rows:
+            # The state it would return to on un-retire, mirroring
+            # api_graduation._prior_state_before_retire's audit lookup.
+            prior = db.conn().execute(
+                """
+                SELECT details FROM actions
+                 WHERE rfc_slug = ? AND action_kind = 'retire'
+                 ORDER BY id DESC LIMIT 1
+                """,
+                (r["slug"],),
+            ).fetchone()
+            restored_state = None
+            if prior and prior["details"]:
+                try:
+                    restored_state = json.loads(prior["details"]).get("prior_state")
+                except (ValueError, TypeError):
+                    restored_state = None
+            if restored_state not in ("super-draft", "active"):
+                restored_state = "active" if r["rfc_id"] else "super-draft"
+            items.append({
+                "slug": r["slug"],
+                "title": r["title"],
+                "id": r["rfc_id"],
+                "owners": json.loads(r["owners_json"] or "[]"),
+                "tags": json.loads(r["tags_json"] or "[]"),
+                "retired_at": r["updated_at"],
+                "restores_to": restored_state,
+            })
+        return {"items": items}
+
     # ----- User search (typeahead for §15.8 mute add) -----
 
     @router.get("/api/users/search")

backend/app/api_branches.py

@@ -29,7 +29,7 @@ from fastapi import APIRouter, HTTPException, Request
 from fastapi.responses import StreamingResponse
 from pydantic import BaseModel, Field
 
-from . import auth, cache, chat as chat_layer, db, entry as entry_mod, funder, models_resolver
+from . import auth, cache, chat as chat_layer, db, entry as entry_mod, funder, models_resolver, projects as projects_mod
 from .bot import Bot
 from .config import Config
 from .gitea import Gitea, GiteaError
@@ -120,7 +120,9 @@ def make_router(
     # -------------------------------------------------------------------
 
     @router.get("/api/rfcs/{slug}/models")
-    async def list_models_for_rfc(slug: str) -> dict[str, Any]:
+    async def list_models_for_rfc(slug: str, request: Request) -> dict[str, Any]:
+        # §22.5 visibility gate (subtractive): gated → 404 to non-members.
+        _require_rfc(slug, auth.current_user(request))
         resolved = models_resolver.resolve_models_for_rfc(slug, providers)
         return {
             "models": [
@@ -140,7 +142,7 @@ def make_router(
     @router.get("/api/rfcs/{slug}/main")
     async def get_rfc_main(slug: str, request: Request) -> dict[str, Any]:
         viewer = auth.current_user(request)
-        rfc = _require_rfc(slug)
+        rfc = _require_rfc(slug, viewer)
         if rfc["state"] not in ("active", "super-draft"):
             raise HTTPException(409, f"RFC is {rfc['state']}")
 
@@ -150,7 +152,7 @@ def make_router(
         # `refresh_meta_branches` writes is internal scaffolding for the
         # §10.1 has-commits-ahead check — the §9.4 dropdown's first
         # position is rendered separately as 'canonical body'.
-        if _is_super_draft(rfc):
+        if _is_meta_resident(rfc):
             branch_rows = db.conn().execute(
                 """
                 SELECT branch_name, head_sha, state, last_commit_at, pinned
@@ -180,7 +182,7 @@ def make_router(
         # per-RFC repo. For super-draft: meta_body_edit and meta_metadata
         # PRs on the meta repo. Same shape either way — the §9.4 dropdown
         # treats both as "open work against this entry."
-        pr_kinds = ("meta_body_edit", "meta_metadata") if _is_super_draft(rfc) else ("rfc_branch",)
+        pr_kinds = ("meta_body_edit", "meta_metadata") if _is_meta_resident(rfc) else ("rfc_branch",)
         placeholders = ",".join("?" * len(pr_kinds))
         pr_rows = db.conn().execute(
             f"""
@@ -204,17 +206,18 @@ def make_router(
             for r in pr_rows
         ]
 
-        # For super-drafts the cached body is entry.body already (see
-        # cache._upsert_cached_rfc), so no extraction is needed.
-        # §9.8 / §13.4 pre-graduation history: for active RFCs, surface
-        # any `threads` or `changes` rows whose `branch_name` starts with
-        # `edit-<slug>-` so the breadcrumb dropdown can render the
-        # affordance as a distinct disclosure alongside main, open
-        # branches, and open PRs. The slug is the canonical key per §2.3
-        # before and after graduation, so the query is a straightforward
-        # lookup — no data movement.
+        # For meta-resident entries the cached body is entry.body already
+        # (see cache._upsert_cached_rfc), so no extraction is needed.
+        # Pre-graduation history is a LEGACY-only affordance: under the
+        # meta-only topology (§1, §13.4) graduation moves nothing, so an
+        # active RFC's edit branches are its *current* branches and already
+        # surface in `branches` above — there is no separate pre-graduation
+        # set. The disclosure is therefore computed only for a legacy
+        # per-RFC-repo active entry (`repo` set), where edit branches on the
+        # meta repo genuinely predate the per-RFC repo and would otherwise
+        # not appear. After the RFC-0001 fold-back (§13.6) nothing matches.
         pre_grad: list[dict[str, Any]] = []
-        if rfc["state"] == "active":
+        if rfc["state"] == "active" and rfc["repo"]:
             pre_grad_rows = db.conn().execute(
                 """
                 SELECT t.branch_name,
@@ -288,12 +291,24 @@ def make_router(
                 403,
                 "This RFC's owner has not invited you to contribute PRs",
             )
-        rfc = _require_active_rfc(slug)
+        rfc = _require_active_rfc(slug, viewer)
         owner, repo = _repo_for(rfc)
         new_branch = (body.branch_name or "").strip()
         if not new_branch:
-            new_branch = _auto_branch_name(viewer.gitea_login)
-        _validate_branch_name(new_branch)
+            # Meta-only topology (§1): an active RFC's branches live on the
+            # shared meta repo, so the auto name must embed the slug for the
+            # cache to attribute it (`edit-<slug>-<hex>`, recovered by
+            # `_slug_from_branch_name`). A legacy per-RFC-repo entry can use
+            # the slug-free `<login>-draft-<hex>` since every branch there
+            # belongs to the one RFC. The auto name is trusted (it carries a
+            # reserved `edit-` prefix by design); only a user-supplied name
+            # is validated, mirroring `start_edit_branch`.
+            new_branch = (
+                _auto_edit_branch_name(slug) if _is_meta_resident(rfc)
+                else _auto_branch_name(viewer.gitea_login)
+            )
+        else:
+            _validate_branch_name(new_branch)
         try:
             await bot.cut_branch_from_main(
                 viewer.as_actor(),
@@ -326,8 +341,10 @@ def make_router(
         _ensure_branch_vis(slug, new_branch, creator_user_id=viewer.user_id)
 
         # Make the cache aware immediately so the breadcrumb reflects
-        # the new branch without waiting for the webhook hop.
-        await cache.refresh_rfc_repo(config, gitea, slug)
+        # the new branch without waiting for the webhook hop. Meta-resident
+        # entries (§1) refresh meta branches; a legacy per-RFC repo refreshes
+        # its own — `_refresh_cache_for` dispatches on residency.
+        await _refresh_cache_for(rfc)
 
         return {"branch_name": new_branch, "slug": slug}
 
@@ -348,7 +365,7 @@ def make_router(
                 403,
                 "This RFC's owner has not invited you to contribute PRs",
             )
-        rfc = _require_super_draft(slug)
+        rfc = _require_super_draft(slug, viewer)
         owner, repo = _repo_for(rfc)
         new_branch = (body.branch_name or "").strip()
         if not new_branch:
@@ -393,7 +410,7 @@ def make_router(
     @router.post("/api/rfcs/{slug}/metadata")
     async def edit_metadata(slug: str, body: MetadataEditBody, request: Request) -> dict[str, Any]:
         viewer = auth.require_contributor(request)
-        rfc = _require_super_draft(slug)
+        rfc = _require_super_draft(slug, viewer)
         # Permission: super-draft owners/arbiters per §6.3, plus app-wide
         # admins/owners per §6.1. Until claim, that collapses to admin/owner.
         if not _can_edit_metadata(rfc, viewer):
@@ -466,7 +483,7 @@ def make_router(
         request: Request,
     ) -> dict[str, Any]:
         viewer = auth.require_contributor(request)
-        rfc = _require_rfc_with_repo(slug)
+        rfc = _require_rfc_with_repo(slug, viewer)
         _require_can_contribute(slug, branch, viewer)
         row = _require_pending_change(slug, branch, change_id)
         if row["kind"] != "ai":
@@ -553,7 +570,7 @@ def make_router(
     @router.post("/api/rfcs/{slug}/branches/{branch:path}/changes/{change_id}/decline")
     async def decline_change(slug: str, branch: str, change_id: int, request: Request) -> dict[str, Any]:
         viewer = auth.require_contributor(request)
-        _require_rfc_with_repo(slug)
+        _require_rfc_with_repo(slug, viewer)
         _require_can_contribute(slug, branch, viewer)
         row = _require_pending_change(slug, branch, change_id)
         if row["kind"] != "ai":
@@ -571,7 +588,7 @@ def make_router(
     @router.post("/api/rfcs/{slug}/branches/{branch:path}/changes/{change_id}/reask")
     async def reask_change(slug: str, branch: str, change_id: int, request: Request) -> dict[str, Any]:
         viewer = auth.require_contributor(request)
-        rfc = _require_rfc_with_repo(slug)
+        rfc = _require_rfc_with_repo(slug, viewer)
         _require_can_contribute(slug, branch, viewer)
         row = _require_change(slug, branch, change_id)
         if row["kind"] != "ai":
@@ -638,7 +655,7 @@ def make_router(
     @router.post("/api/rfcs/{slug}/branches/{branch:path}/manual-flush")
     async def manual_flush(slug: str, branch: str, body: ManualFlushBody, request: Request) -> dict[str, Any]:
         viewer = auth.require_contributor(request)
-        rfc = _require_rfc_with_repo(slug)
+        rfc = _require_rfc_with_repo(slug, viewer)
         _require_can_contribute(slug, branch, viewer)
         owner, repo = _repo_for(rfc, branch)
         path = _file_path_for(rfc, branch)
@@ -715,7 +732,7 @@ def make_router(
     @router.post("/api/rfcs/{slug}/branches/{branch:path}/visibility")
     async def set_branch_visibility(slug: str, branch: str, body: VisibilityBody, request: Request) -> dict[str, Any]:
         viewer = auth.require_contributor(request)
-        rfc = _require_rfc_with_repo(slug)
+        rfc = _require_rfc_with_repo(slug, viewer)
         creator = _branch_creator(slug, branch)
         _require_branch_owner(rfc, viewer, creator)
         current = _branch_vis(slug, branch)
@@ -725,7 +742,7 @@ def make_router(
             """
             INSERT INTO branch_visibility (rfc_slug, branch_name, read_public, contribute_mode)
             VALUES (?, ?, ?, ?)
-            ON CONFLICT(rfc_slug, branch_name) DO UPDATE SET
+            ON CONFLICT(collection_id, rfc_slug, branch_name) DO UPDATE SET
                 read_public = excluded.read_public,
                 contribute_mode = excluded.contribute_mode
             """,
@@ -736,7 +753,7 @@ def make_router(
     @router.post("/api/rfcs/{slug}/branches/{branch:path}/grants")
     async def add_branch_grant(slug: str, branch: str, body: GrantBody, request: Request) -> dict[str, Any]:
         viewer = auth.require_contributor(request)
-        rfc = _require_rfc_with_repo(slug)
+        rfc = _require_rfc_with_repo(slug, viewer)
         creator = _branch_creator(slug, branch)
         _require_branch_owner(rfc, viewer, creator)
         grantee = db.conn().execute(
@@ -757,7 +774,7 @@ def make_router(
     @router.delete("/api/rfcs/{slug}/branches/{branch:path}/grants/{grantee_login}")
     async def revoke_branch_grant(slug: str, branch: str, grantee_login: str, request: Request) -> dict[str, Any]:
         viewer = auth.require_contributor(request)
-        rfc = _require_rfc_with_repo(slug)
+        rfc = _require_rfc_with_repo(slug, viewer)
         creator = _branch_creator(slug, branch)
         _require_branch_owner(rfc, viewer, creator)
         grantee = db.conn().execute(
@@ -777,7 +794,7 @@ def make_router(
     @router.get("/api/rfcs/{slug}/branches/{branch:path}/threads")
     async def list_branch_threads(slug: str, branch: str, request: Request) -> dict[str, Any]:
         viewer = auth.current_user(request)
-        _require_rfc_with_repo(slug)
+        _require_rfc_with_repo(slug, viewer)
         if not _can_read_branch(slug, branch, viewer):
             raise HTTPException(403, "Branch is private")
         rows = db.conn().execute(
@@ -795,7 +812,7 @@ def make_router(
     @router.post("/api/rfcs/{slug}/branches/{branch:path}/threads")
     async def create_branch_thread(slug: str, branch: str, body: ThreadCreateBody, request: Request) -> dict[str, Any]:
         viewer = auth.require_contributor(request)
-        _require_rfc_with_repo(slug)
+        _require_rfc_with_repo(slug, viewer)
         if body.thread_kind == "flag" and not body.label:
             raise HTTPException(422, "Flag threads require a label")
         cur = db.conn().execute(
@@ -825,7 +842,7 @@ def make_router(
     @router.get("/api/rfcs/{slug}/branches/{branch:path}/threads/{thread_id}/messages")
     async def get_thread_messages(slug: str, branch: str, thread_id: int, request: Request) -> dict[str, Any]:
         viewer = auth.current_user(request)
-        _require_rfc_with_repo(slug)
+        _require_rfc_with_repo(slug, viewer)
         if not _can_read_branch(slug, branch, viewer):
             raise HTTPException(403, "Branch is private")
         thread = _require_thread(slug, branch, thread_id)
@@ -850,7 +867,7 @@ def make_router(
         slug: str, branch: str, thread_id: int, body: ThreadMessageBody, request: Request
     ) -> dict[str, Any]:
         viewer = auth.require_contributor(request)
-        _require_rfc_with_repo(slug)
+        _require_rfc_with_repo(slug, viewer)
         _require_thread(slug, branch, thread_id)
         if not _can_read_branch(slug, branch, viewer):
             raise HTTPException(403, "Branch is private")
@@ -871,7 +888,7 @@ def make_router(
         to this (slug, branch) on or before the new cursor is marked read.
         """
         viewer = auth.require_user(request)
-        _require_rfc_with_repo(slug)
+        _require_rfc_with_repo(slug, viewer)
         if not _can_read_branch(slug, branch, viewer):
             raise HTTPException(403, "Branch is private")
         last_seen = int(body.get("last_seen_message_id") or 0) or None
@@ -879,7 +896,7 @@ def make_router(
             """
             INSERT INTO branch_chat_seen (user_id, rfc_slug, branch_name, last_seen_message_id, seen_at)
             VALUES (?, ?, ?, ?, datetime('now'))
-            ON CONFLICT(user_id, rfc_slug, branch_name) DO UPDATE SET
+            ON CONFLICT(collection_id, user_id, rfc_slug, branch_name) DO UPDATE SET
                 last_seen_message_id = excluded.last_seen_message_id,
                 seen_at = excluded.seen_at
             """,
@@ -894,7 +911,7 @@ def make_router(
     @router.post("/api/rfcs/{slug}/branches/{branch:path}/threads/{thread_id}/resolve")
     async def resolve_thread(slug: str, branch: str, thread_id: int, request: Request) -> dict[str, Any]:
         viewer = auth.require_contributor(request)
-        rfc = _require_rfc_with_repo(slug)
+        rfc = _require_rfc_with_repo(slug, viewer)
         thread = _require_thread(slug, branch, thread_id)
         creator = _branch_creator(slug, branch)
         if not _can_resolve_thread(rfc, thread, creator, viewer):
@@ -917,7 +934,7 @@ def make_router(
         slug: str, branch: str, thread_id: int, body: ChatTurnBody, request: Request
     ):
         viewer = auth.require_contributor(request)
-        rfc = _require_rfc_with_repo(slug)
+        rfc = _require_rfc_with_repo(slug, viewer)
         thread = _require_thread(slug, branch, thread_id)
         if not _can_read_branch(slug, branch, viewer):
             raise HTTPException(403, "Branch is private")
@@ -1003,7 +1020,7 @@ def make_router(
     @router.get("/api/rfcs/{slug}/branches/{branch:path}")
     async def get_branch_view(slug: str, branch: str, request: Request) -> dict[str, Any]:
         viewer = auth.current_user(request)
-        rfc = _require_rfc_with_repo(slug)
+        rfc = _require_rfc_with_repo(slug, viewer)
         if not _can_read_branch(slug, branch, viewer):
             raise HTTPException(403, "Branch is private")
 
@@ -1074,31 +1091,34 @@ def make_router(
     # Permission + state helpers (closures, share `config` etc.)
     # ------------------------------------------------------------------
 
-    def _require_rfc(slug: str):
-        row = db.conn().execute("SELECT * FROM cached_rfcs WHERE slug = ?", (slug,)).fetchone()
+    def _require_rfc(slug: str, viewer):
+        row = db.conn().execute("SELECT *, (SELECT c.project_id FROM collections c WHERE c.id = cached_rfcs.collection_id) AS project_id FROM cached_rfcs WHERE slug = ?", (slug,)).fetchone()
         if row is None:
             raise HTTPException(404, "RFC not found")
+        # §22.5 visibility gate (subtractive, §22.7): a gated project's entries
+        # 404 to non-members — indistinguishable from an unknown slug.
+        auth.require_project_readable(viewer, row["project_id"])
         return row
 
-    def _require_rfc_with_repo(slug: str):
-        """Used by every branch-scoped endpoint. For active RFCs, a repo is
-        required. For super-drafts, the meta repo is the implicit target —
-        no per-RFC repo check needed."""
-        row = _require_rfc(slug)
+    def _require_rfc_with_repo(slug: str, viewer):
+        """Used by every branch-scoped endpoint. Under the meta-only
+        topology (§1) the meta repo is the implicit target for every
+        entry — super-draft and active alike — so there is no per-RFC
+        repo check. The name is retained for call-site stability; a
+        withdrawn entry is still rejected."""
+        row = _require_rfc(slug, viewer)
         if row["state"] == "withdrawn":
             raise HTTPException(409, "RFC is withdrawn")
-        if row["state"] == "active" and not row["repo"]:
-            raise HTTPException(409, "RFC has no repo")
         return row
 
-    def _require_active_rfc(slug: str):
-        row = _require_rfc_with_repo(slug)
+    def _require_active_rfc(slug: str, viewer):
+        row = _require_rfc_with_repo(slug, viewer)
         if row["state"] != "active":
             raise HTTPException(409, f"RFC is {row['state']}, not active")
         return row
 
-    def _require_super_draft(slug: str):
-        row = _require_rfc(slug)
+    def _require_super_draft(slug: str, viewer):
+        row = _require_rfc(slug, viewer)
         if row["state"] != "super-draft":
             raise HTTPException(409, f"RFC is {row['state']}, not super-draft")
         return row
@@ -1106,28 +1126,34 @@ def make_router(
     def _is_super_draft(rfc) -> bool:
         return rfc["state"] == "super-draft"
 
+    def _is_meta_resident(rfc) -> bool:
+        """Meta-only topology (§1): an entry lives in the meta repo's
+        `rfcs/<slug>.md` (super-draft or active-in-place) unless it carries
+        a legacy per-RFC `repo:` — which nothing does after the RFC-0001
+        fold-back (§13.6)."""
+        return not rfc["repo"]
+
     def _is_meta_branch_name(name: str) -> bool:
         """A branch name shaped like one of the bot's meta-repo prefixes.
-        §9.8's pre-graduation history affordance points the new RFC view
-        at branches matching `edit-<slug>-...` even after the entry is
-        active; treating those names as meta-repo targets lets the read
-        path dispatch correctly without a separate endpoint."""
+        Retained for the legacy per-RFC-repo read path; under meta-only
+        every entry is already a meta target via `_is_meta_resident`."""
         return name != "main" and name.startswith((
             "edit-", "edit/", "metadata-", "metadata/", "claim/", "propose/",
             "graduate-",
         ))
 
     def _is_meta_target(rfc, branch: str) -> bool:
-        """Either a super-draft branch (active edit branch or the
-        canonical body) or an active RFC's pre-graduation meta-repo
-        branch surfaced through the §9.8 history affordance."""
-        if _is_super_draft(rfc):
+        """A meta-resident entry (super-draft or active-in-place, §1)
+        targets the meta repo for every branch. The branch-name fallback
+        covers the retired per-RFC-repo case for any legacy entry that
+        still carries a `repo:`."""
+        if _is_meta_resident(rfc):
             return True
         return _is_meta_branch_name(branch)
 
     def _repo_for(rfc, branch: str = "main") -> tuple[str, str]:
         if _is_meta_target(rfc, branch):
-            return config.gitea_org, config.meta_repo
+            return config.gitea_org, (projects_mod.default_content_repo(config) or "")
         owner, repo = rfc["repo"].split("/", 1)
         return owner, repo
 
@@ -1161,7 +1187,7 @@ def make_router(
         return entry_mod.serialize(entry)
 
     async def _refresh_cache_for(rfc) -> None:
-        if _is_super_draft(rfc):
+        if _is_meta_resident(rfc):
             await cache.refresh_meta_repo(config, gitea)
             await cache.refresh_meta_branches(config, gitea)
         else:
@@ -1238,6 +1264,12 @@ def make_router(
         return row["on_behalf_of"] if row else None
 
     def _can_read_branch(slug: str, branch: str, viewer) -> bool:
+        # §22.5 visibility gate first (subtractive, §B.2): in a hidden/gated
+        # collection nothing — not even main or a read_public branch — is
+        # readable by a non-scope-role viewer.
+        cid = auth.collection_of_rfc(slug)
+        if not auth.can_read_collection(viewer, cid):
+            return False
         if branch == "main":
             return True
         vis = _branch_vis(slug, branch)
@@ -1245,7 +1277,7 @@ def make_router(
             return True
         if viewer is None:
             return False
-        if viewer.role in ("owner", "admin"):
+        if auth.is_collection_superuser(viewer, cid):
             return True
         creator = _branch_creator(slug, branch)
         if creator and viewer.gitea_login == creator:
@@ -1270,14 +1302,20 @@ def make_router(
             return False
         if branch == "main":
             return False
-        # §9.8: pre-graduation history branches are read-only on the
-        # post-graduation surface. The contributor can re-cut against the
-        # new repo's main if they still want the work, but the meta-repo
-        # branches that lived on the super-draft are not editable from
-        # the active-RFC view.
-        if rfc["state"] == "active" and _is_meta_branch_name(branch):
+        # §9.8 (LEGACY per-repo only): pre-graduation history branches are
+        # read-only on the post-graduation surface of a per-RFC-repo active
+        # entry. Under the meta-only topology (§1, §13.4) an active RFC's
+        # `edit-<slug>-…` branches are its *current* editable branches, not
+        # a frozen pre-graduation set, so this guard applies only when a
+        # legacy `repo:` is set (nothing, after the RFC-0001 fold-back).
+        if rfc["state"] == "active" and rfc["repo"] and _is_meta_branch_name(branch):
             return False
-        if viewer.role in ("owner", "admin"):
+        cid = auth.collection_of_rfc(slug)
+        # §22.5 visibility gate (subtractive): no contribute in an unreadable
+        # collection.
+        if not auth.can_read_collection(viewer, cid):
+            return False
+        if auth.is_collection_superuser(viewer, cid):
             return True
         owners = json.loads(rfc["owners_json"] or "[]")
         arbiters = json.loads(rfc["arbiters_json"] or "[]")
@@ -1288,7 +1326,10 @@ def make_router(
             return True
         vis = _branch_vis(slug, branch)
         if vis["contribute_mode"] == "any-contributor":
-            return True
+            # "any contributor" means anyone with collection-level write standing
+            # (§B.2) — the grandfathered baseline on the public default
+            # collection, or an explicit scope grant reaching the collection.
+            return auth.can_contribute_in_collection(viewer, cid)
         if vis["contribute_mode"] == "specific":
             row = db.conn().execute(
                 """
@@ -1302,14 +1343,16 @@ def make_router(
 
     def _require_can_contribute(slug: str, branch: str, viewer) -> None:
         rfc = db.conn().execute(
-            "SELECT state, owners_json, arbiters_json FROM cached_rfcs WHERE slug = ?",
+            "SELECT state, repo, owners_json, arbiters_json FROM cached_rfcs WHERE slug = ?",
             (slug,),
         ).fetchone()
         if not _can_contribute(rfc, slug, branch, viewer):
             raise HTTPException(403, "You do not have contribute access to this branch")
 
     def _require_branch_owner(rfc, viewer, creator: str | None) -> None:
-        if viewer.role in ("owner", "admin"):
+        # §22.6: a project_admin is the per-RFC owner/arbiter authority lifted
+        # to project scope, so it (and a deployment owner/admin) clears here.
+        if auth.is_collection_superuser(viewer, rfc["collection_id"]):
             return
         owners = json.loads(rfc["owners_json"] or "[]")
         arbiters = json.loads(rfc["arbiters_json"] or "[]")
@@ -1320,11 +1363,12 @@ def make_router(
         raise HTTPException(403, "Only the branch creator, an RFC owner/arbiter, or an admin/owner may change branch settings")
 
     def _can_edit_metadata(rfc, viewer) -> bool:
-        """§9.5: super-draft owners/arbiters per §6.3 plus app admins/owners.
-        Until §13.1's claim runs, the super-draft has no owners, so the set
-        collapses to app admins/owners only — sensible because admin oversight
-        is the only path to canonicalizing edits on an unclaimed entry."""
-        if viewer.role in ("owner", "admin"):
+        """§9.5: super-draft owners/arbiters per §6.3 plus project_admin /
+        app admins/owners (§22.6). Until §13.1's claim runs, the super-draft
+        has no owners, so the set collapses to the superuser tier only —
+        sensible because admin oversight is the only path to canonicalizing
+        edits on an unclaimed entry."""
+        if auth.is_collection_superuser(viewer, rfc["collection_id"]):
             return True
         owners = json.loads(rfc["owners_json"] or "[]")
         arbiters = json.loads(rfc["arbiters_json"] or "[]")
@@ -1337,7 +1381,7 @@ def make_router(
             "can_read": _can_read_branch(slug, branch, viewer),
             "can_contribute": _can_contribute(rfc, slug, branch, viewer) if viewer else False,
             "can_change_branch_settings": viewer is not None and (
-                viewer.role in ("owner", "admin")
+                auth.is_collection_superuser(viewer, rfc["collection_id"])
                 or (creator is not None and viewer.gitea_login == creator)
                 or viewer.gitea_login in (owners + arbiters)
             ),
@@ -1383,7 +1427,7 @@ def make_router(
     def _can_resolve_thread(rfc, thread, creator: str | None, viewer) -> bool:
         if viewer is None:
             return False
-        if viewer.role in ("owner", "admin"):
+        if auth.is_collection_superuser(viewer, rfc["collection_id"]):
             return True
         owners = json.loads(rfc["owners_json"] or "[]")
         arbiters = json.loads(rfc["arbiters_json"] or "[]")

backend/app/api_collections.py

@@ -0,0 +1,182 @@
+"""§22 S2 — collection directory + create-collection.
+
+GET  /api/projects/:id/collections        — list the project's visible collections.
+GET  /api/projects/:id/collections/:cid    — one collection's settings.
+POST /api/projects/:id/collections         — create a collection. Authorized by a
+                                             deployment owner/admin (S2; scoped
+                                             {owner, contributor} roles at the
+                                             collection axis land in S3). The bot
+                                             commits a `.collection.yaml` to the
+                                             content repo, then the registry mirror
+                                             upserts the collections row — §22.2
+                                             keeps the registry the source of truth.
+"""
+from __future__ import annotations
+
+import re
+from typing import Any
+
+import yaml
+from fastapi import APIRouter, HTTPException, Request
+from pydantic import BaseModel
+
+from . import (
+    auth,
+    collections as collections_mod,
+    projects as projects_mod,
+    registry as registry_mod,
+)
+from .bot import Bot
+from .config import Config
+from .gitea import Gitea, GiteaError
+
+_SLUG_RE = re.compile(r"^[a-z0-9](?:[a-z0-9-]*[a-z0-9])?$")
+
+
+class CreateCollectionBody(BaseModel):
+    collection_id: str
+    type: str
+    name: str | None = None
+    visibility: str | None = None
+    initial_state: str | None = None
+
+
+def _project_viewer_caps(viewer: Any, project_id: str) -> dict[str, Any]:
+    """§22 S4: the viewer's project-grain capabilities for role-aware UI — may
+    they create a collection, may they manage membership (invite), and their
+    project role. `role` maps the §22.6 legacy strings back to the unified
+    `{owner, contributor}` vocabulary the frontend speaks."""
+    legacy = auth.project_member_role(viewer, project_id)
+    role = None
+    if viewer is not None and viewer.role in ("owner", "admin"):
+        role = "owner"
+    elif legacy == "project_admin":
+        role = "owner"
+    elif legacy == "project_contributor":
+        role = "contributor"
+    return {
+        "can_create_collection": auth.can_create_collection(viewer, project_id),
+        "can_invite": auth.can_invite_at_project(viewer, project_id),
+        # §22.8: a signed-in, granted account with no role at the project may ask
+        # to join it (the request-to-join affordance). Owners/members and
+        # not-yet-granted accounts don't see it.
+        "can_request_join": (
+            viewer is not None
+            and viewer.permission_state == "granted"
+            and auth.effective_role_at_scope(viewer, "project", project_id) is None
+        ),
+        "role": role,
+    }
+
+
+def make_router(config: Config, gitea: Gitea, bot: Bot) -> APIRouter:
+    router = APIRouter()
+
+    @router.get("/api/projects/{project_id}/collections")
+    async def list_cols(project_id: str, request: Request) -> dict[str, Any]:
+        viewer = auth.current_user(request)
+        # §22.5 read gate: a gated project 404s a non-member.
+        auth.require_project_readable(viewer, project_id)
+        # §22.5 (S3): the directory is viewer-aware — a hidden/gated collection
+        # is listed only for a scope-role holder who can read it; `unlisted` is
+        # omitted from enumeration for everyone (link-only).
+        items = [
+            c
+            for c in collections_mod.list_collections(project_id, include_unlisted=True)
+            if c["visibility"] != "unlisted" and auth.can_read_collection(viewer, c["id"])
+        ]
+        # §22 S4: surface the viewer's project-level capabilities so the
+        # directory can render role-aware affordances (the create-first-
+        # collection CTA, the invite control) without a second round-trip.
+        return {"items": items, "viewer": _project_viewer_caps(viewer, project_id)}
+
+    @router.get("/api/projects/{project_id}/collections/{collection_id}")
+    async def get_col(project_id: str, collection_id: str, request: Request) -> dict[str, Any]:
+        viewer = auth.current_user(request)
+        auth.require_project_readable(viewer, project_id)
+        col = collections_mod.get_collection(collection_id)
+        if col is None or col["project_id"] != project_id:
+            raise HTTPException(404, "Not found")
+        # §22.5 (S3): a hidden/gated collection 404s a non-scope-role viewer.
+        auth.require_collection_readable(viewer, collection_id)
+        # §22 S4: the viewer's collection-level capabilities drive the
+        # propose-first empty state and the collection invite control.
+        col = dict(col)
+        col["viewer"] = {
+            "can_contribute": auth.can_contribute_in_collection(viewer, collection_id),
+            "can_invite": auth.can_invite_at_collection(viewer, collection_id),
+            # §22.8: a signed-in, granted account with no role reaching this
+            # collection may ask to join it.
+            "can_request_join": (
+                viewer is not None
+                and viewer.permission_state == "granted"
+                and auth.effective_scope_role(viewer, collection_id) is None
+            ),
+            "role": auth.effective_scope_role(viewer, collection_id),
+        }
+        return col
+
+    @router.post("/api/projects/{project_id}/collections")
+    async def create_col(
+        project_id: str, body: CreateCollectionBody, request: Request
+    ) -> dict[str, Any]:
+        # §B.1 (S3) authority: a deployment owner/admin or a project/global-scope
+        # grant holder (Owner or RFC Contributor) may create a collection. The
+        # read gate runs first so a gated project 404s a non-member.
+        user = auth.require_contributor(request)
+        auth.require_project_readable(user, project_id)
+        if not auth.can_create_collection(user, project_id):
+            raise HTTPException(403, "You may not create collections in this project")
+        cid = body.collection_id.strip().lower()
+        if not _SLUG_RE.match(cid) or cid == "default":
+            raise HTTPException(422, "collection id must be a slug and not 'default'")
+        if body.type not in registry_mod.VALID_TYPES:
+            raise HTTPException(422, f"invalid type {body.type!r}")
+        if body.visibility is not None:
+            if body.visibility not in registry_mod.VALID_VISIBILITY:
+                raise HTTPException(422, f"invalid visibility {body.visibility!r}")
+            # §22.5 (S3) strictness: a collection may be set only as strict or
+            # stricter than its project — never more public.
+            pvis = auth.project_visibility(project_id)
+            if auth.visibility_rank(body.visibility) < auth.visibility_rank(pvis):
+                raise HTTPException(
+                    422,
+                    f"collection visibility {body.visibility!r} is looser than "
+                    f"the project's {pvis!r}; a collection may only narrow it",
+                )
+        if body.initial_state is not None and body.initial_state not in registry_mod.VALID_INITIAL_STATE:
+            raise HTTPException(422, f"invalid initial_state {body.initial_state!r}")
+        if collections_mod.get_collection(cid) is not None:
+            raise HTTPException(409, f"collection `{cid}` already exists")
+        content_repo = projects_mod.content_repo(project_id)
+        if not content_repo:
+            raise HTTPException(409, "project has no content repo")
+
+        manifest: dict[str, Any] = {"type": body.type}
+        if body.name:
+            manifest["name"] = body.name
+        if body.visibility:
+            manifest["visibility"] = body.visibility
+        if body.initial_state:
+            manifest["initial_state"] = body.initial_state
+        manifest_yaml = yaml.safe_dump(manifest, sort_keys=False)
+
+        try:
+            await bot.create_collection(
+                user.as_actor(),
+                org=config.gitea_org,
+                content_repo=content_repo,
+                collection_id=cid,
+                manifest_yaml=manifest_yaml,
+            )
+        except GiteaError as e:
+            raise HTTPException(502, f"Gitea: {e.detail}")
+
+        # §22.2: re-read the registry so the new manifest becomes a row.
+        await registry_mod.refresh_registry(config, gitea)
+        col = collections_mod.get_collection(cid)
+        if col is None:
+            raise HTTPException(500, "collection committed but not mirrored")
+        return col
+
+    return router

backend/app/api_contributions.py

@@ -0,0 +1,316 @@
+"""v0.29.0 / roadmap #28 Part 3 — offer-to-contribute-to-a-pending-RFC.
+
+When the #28 scanner (see ``rfc_links.py``) matches a term in submitted
+PR/comment text to a **pending** RFC — a super-draft
+(``cached_rfcs.state='super-draft'``: accepted as an idea, owned, with a
+contribution surface, but not yet graduated to an active RFC) — the
+reader is offered an "ask to contribute" popover. This module is the
+backend for that flow:
+
+  * ``GET  /api/rfcs/{slug}/contribution-target``      — what the
+    contribute form needs (RFC title, owner display, the viewer's
+    eligibility + whether they already have a pending ask).
+  * ``POST /api/rfcs/{slug}/contribution-requests``    — submit the ask
+    (who-I-am / why / optional use-case); lands a row + one §15
+    notification per owner.
+  * ``POST /api/rfcs/{slug}/contribution-requests/{id}/accept``  — owner:
+    accept, which fires #12's owner-invite flow with the requester as the
+    invitee (opening the RFC's discussion/contribution surface), then
+    echoes a notification back to the requester.
+  * ``POST /api/rfcs/{slug}/contribution-requests/{id}/decline`` — owner:
+    decline; the request closes and the requester is notified.
+
+"Pending" is scoped to a super-draft because that is the state with an
+owner to route to, a contribution surface to open, and a row in
+``cached_rfcs`` for the ``rfc_invitations`` FK the accept path reuses.
+Pre-merge idea PRs are deliberately out of scope (no contribution
+surface yet) — a documented future extension, mirroring the
+conservative scoping in ``rfc_links.py``.
+"""
+from __future__ import annotations
+
+import sqlite3
+from typing import Any
+
+from fastapi import APIRouter, HTTPException, Request
+from pydantic import BaseModel, Field
+
+from . import api_invitations, auth, db, notify
+
+# Field caps — generous for free text, bounded so a request row (and the
+# notification payload that carries it) can't be used to store unbounded
+# blobs. Mirrors the order-of-magnitude of the propose/tag-suggest caps.
+_WHO_MAX = 2000
+_WHY_MAX = 4000
+_USE_CASE_MAX = 4000
+_TERM_MAX = 200
+
+
+class ContributionRequestBody(BaseModel):
+    # The term in the PR/comment text that surfaced the offer (the
+    # super-draft's title/slug). Carried for the owner's context line.
+    matched_term: str = Field(min_length=1, max_length=_TERM_MAX)
+    who_i_am: str = Field(min_length=1, max_length=_WHO_MAX)
+    why: str = Field(min_length=1, max_length=_WHY_MAX)
+    use_case: str | None = Field(default=None, max_length=_USE_CASE_MAX)
+
+
+def _require_super_draft(slug: str, viewer):
+    """The contribute surface only operates on a *pending* RFC. 404 on
+    unknown; 409 on a state that isn't a super-draft (active RFCs use the
+    Part-1 link, not a contribute offer; withdrawn is closed). The §22.5
+    visibility gate is subtractive: a gated project's entries 404 to
+    non-members (§22.7)."""
+    row = db.conn().execute(
+        "SELECT slug, title, state, owners_json, proposed_by, (SELECT c.project_id FROM collections c WHERE c.id = cached_rfcs.collection_id) AS project_id FROM cached_rfcs WHERE slug = ?",
+        (slug,),
+    ).fetchone()
+    if row is None:
+        raise HTTPException(404, "RFC not found")
+    auth.require_project_readable(viewer, row["project_id"])
+    if row["state"] != "super-draft":
+        raise HTTPException(409, "RFC is not a pending super-draft")
+    return row
+
+
+def _require_request(slug: str, request_id: int):
+    row = db.conn().execute(
+        """
+        SELECT id, rfc_slug, requester_user_id, matched_term, who_i_am, why,
+               use_case, status
+          FROM contribution_requests WHERE id = ? AND rfc_slug = ?
+        """,
+        (request_id, slug),
+    ).fetchone()
+    if row is None:
+        raise HTTPException(404, "Contribution request not found")
+    return row
+
+
+def _viewer_relationship(viewer, slug: str) -> str | None:
+    """Why this viewer can't *request* to contribute — or None if they can.
+    Owners/admins already have the RFC; existing collaborators are already
+    in. Both get a clear 409 rather than a useless self-request."""
+    if auth.is_rfc_owner(viewer, slug) or auth.is_collection_superuser(viewer, auth.collection_of_rfc(slug)):
+        return "You already own or administer this RFC."
+    if auth.is_rfc_collaborator(viewer, slug):
+        return "You're already a collaborator on this RFC."
+    return None
+
+
+def make_router() -> APIRouter:
+    router = APIRouter()
+
+    # ---------------------------------------------------------------
+    # GET — what the contribute form needs to render + gate itself.
+    # ---------------------------------------------------------------
+
+    @router.get("/api/rfcs/{slug}/contribution-target")
+    async def contribution_target(slug: str, request: Request) -> dict[str, Any]:
+        row = db.conn().execute(
+            "SELECT slug, title, state, owners_json, proposed_by, (SELECT c.project_id FROM collections c WHERE c.id = cached_rfcs.collection_id) AS project_id FROM cached_rfcs WHERE slug = ?",
+            (slug,),
+        ).fetchone()
+        if row is None:
+            raise HTTPException(404, "RFC not found")
+        viewer = auth.current_user(request)
+        # §22.5 visibility gate (subtractive): gated → 404 to non-members.
+        auth.require_project_readable(viewer, row["project_id"])
+
+        from . import rfc_links  # local import: avoid a module import cycle
+
+        owner = rfc_links._owner_display(db.conn(), row["owners_json"], row["proposed_by"])
+
+        eligible = True
+        reason: str | None = None
+        already_requested = False
+        if row["state"] != "super-draft":
+            eligible, reason = False, "This RFC is no longer pending."
+        elif viewer is None:
+            eligible, reason = False, "Sign in to ask to contribute."
+        elif viewer.permission_state != "granted":
+            eligible, reason = False, "Your beta access request is in review."
+        else:
+            reason = _viewer_relationship(viewer, slug)
+            if reason is not None:
+                eligible = False
+            else:
+                already_requested = bool(
+                    db.conn().execute(
+                        """
+                        SELECT 1 FROM contribution_requests
+                         WHERE rfc_slug = ? AND requester_user_id = ? AND status = 'pending'
+                         LIMIT 1
+                        """,
+                        (slug, viewer.user_id),
+                    ).fetchone()
+                )
+
+        return {
+            "slug": row["slug"],
+            "title": row["title"],
+            "owner": owner,
+            "eligible": eligible and not already_requested,
+            "reason": reason,
+            "already_requested": already_requested,
+        }
+
+    # ---------------------------------------------------------------
+    # POST — submit a contribute request.
+    # ---------------------------------------------------------------
+
+    @router.post("/api/rfcs/{slug}/contribution-requests")
+    async def create_contribution_request(
+        slug: str, body: ContributionRequestBody, request: Request
+    ) -> dict[str, Any]:
+        viewer = auth.require_contributor(request)
+        _require_super_draft(slug, viewer)
+
+        reason = _viewer_relationship(viewer, slug)
+        if reason is not None:
+            raise HTTPException(409, reason)
+
+        who_i_am = body.who_i_am.strip()
+        why = body.why.strip()
+        use_case = (body.use_case or "").strip() or None
+        matched_term = body.matched_term.strip()
+        if not who_i_am or not why:
+            raise HTTPException(422, "Both 'who I am' and 'why' are required.")
+
+        try:
+            cur = db.conn().execute(
+                """
+                INSERT INTO contribution_requests
+                    (rfc_slug, requester_user_id, matched_term, who_i_am, why, use_case)
+                VALUES (?, ?, ?, ?, ?, ?)
+                """,
+                (slug, viewer.user_id, matched_term, who_i_am, why, use_case),
+            )
+        except sqlite3.IntegrityError:
+            # The partial unique index — one open request per (RFC, user).
+            raise HTTPException(409, "You already have a pending request to contribute to this RFC.")
+        request_id = cur.lastrowid
+
+        # One actionable notification per owner; stamp the first onto the
+        # row as the inbox-action handle (any owner can act on the request).
+        notif_ids = notify.fan_out_contribution_request(
+            rfc_slug=slug,
+            requester_user_id=viewer.user_id,
+            request_id=request_id,
+            matched_term=matched_term,
+            who_i_am=who_i_am,
+            why=why,
+            use_case=use_case,
+        )
+        if notif_ids:
+            db.conn().execute(
+                "UPDATE contribution_requests SET notification_id = ? WHERE id = ?",
+                (notif_ids[0], request_id),
+            )
+
+        return {"id": request_id, "rfc_slug": slug, "status": "pending"}
+
+    # ---------------------------------------------------------------
+    # POST — owner accepts → fire #12's invite flow.
+    # ---------------------------------------------------------------
+
+    @router.post("/api/rfcs/{slug}/contribution-requests/{request_id}/accept")
+    async def accept_contribution_request(
+        slug: str, request_id: int, request: Request
+    ) -> dict[str, Any]:
+        viewer = auth.require_contributor(request)
+        rfc = _require_super_draft(slug, viewer)
+        if not auth.can_invite_to_rfc(viewer, slug):
+            raise HTTPException(403, "Only the RFC's owner can act on contribution requests")
+
+        req = _require_request(slug, request_id)
+        if req["status"] != "pending":
+            raise HTTPException(409, f"This request was already {req['status']}.")
+
+        requester = db.conn().execute(
+            "SELECT id, email FROM users WHERE id = ?", (req["requester_user_id"],)
+        ).fetchone()
+        if requester is None or not (requester["email"] or "").strip():
+            raise HTTPException(422, "The requester has no email address on file to invite.")
+
+        # Fire #12's owner-invite flow with the requester as the invitee.
+        # If a pending contributor invitation already exists (the owner
+        # invited them out-of-band first), reuse it rather than failing.
+        try:
+            invitation = api_invitations.issue_invitation(
+                slug=slug,
+                inviter_user_id=viewer.user_id,
+                inviter_display=viewer.display_name or viewer.gitea_login or "An RFC owner",
+                invitee_email=requester["email"],
+                role_in_rfc="contributor",
+                rfc_title=rfc["title"],
+            )
+            invitation_id = invitation["id"]
+        except HTTPException as exc:
+            if exc.status_code != 409:
+                raise
+            existing = db.conn().execute(
+                """
+                SELECT id FROM rfc_invitations
+                 WHERE rfc_slug = ? AND invitee_email = ? COLLATE NOCASE
+                   AND role_in_rfc = 'contributor' AND status = 'pending'
+                 ORDER BY id DESC LIMIT 1
+                """,
+                (slug, requester["email"].strip()),
+            ).fetchone()
+            invitation_id = existing["id"] if existing else None
+
+        db.conn().execute(
+            """
+            UPDATE contribution_requests
+               SET status = 'accepted', decided_at = datetime('now'),
+                   decided_by_user_id = ?, invitation_id = ?
+             WHERE id = ?
+            """,
+            (viewer.user_id, invitation_id, request_id),
+        )
+        notify.notify_contribution_decided(
+            rfc_slug=slug,
+            requester_user_id=req["requester_user_id"],
+            decider_user_id=viewer.user_id,
+            request_id=request_id,
+            accepted=True,
+        )
+        return {"ok": True, "status": "accepted", "invitation_id": invitation_id}
+
+    # ---------------------------------------------------------------
+    # POST — owner declines.
+    # ---------------------------------------------------------------
+
+    @router.post("/api/rfcs/{slug}/contribution-requests/{request_id}/decline")
+    async def decline_contribution_request(
+        slug: str, request_id: int, request: Request
+    ) -> dict[str, Any]:
+        viewer = auth.require_contributor(request)
+        _require_super_draft(slug, viewer)
+        if not auth.can_invite_to_rfc(viewer, slug):
+            raise HTTPException(403, "Only the RFC's owner can act on contribution requests")
+
+        req = _require_request(slug, request_id)
+        if req["status"] != "pending":
+            raise HTTPException(409, f"This request was already {req['status']}.")
+
+        db.conn().execute(
+            """
+            UPDATE contribution_requests
+               SET status = 'declined', decided_at = datetime('now'),
+                   decided_by_user_id = ?
+             WHERE id = ?
+            """,
+            (viewer.user_id, request_id),
+        )
+        notify.notify_contribution_decided(
+            rfc_slug=slug,
+            requester_user_id=req["requester_user_id"],
+            decider_user_id=viewer.user_id,
+            request_id=request_id,
+            accepted=False,
+        )
+        return {"ok": True, "status": "declined"}
+
+    return router

backend/app/api_deployment.py

@@ -0,0 +1,263 @@
+"""§22.9 runtime deployment/project config (replaces VITE_APP_NAME) + §22.10
+old-URL 308 redirects + §22 S5 in-app create-project.
+
+GET  /api/deployment — the deployment name/tagline + the projects the caller can
+see (§22.5: gated filtered by membership, unlisted omitted from enumeration),
+plus the corpus-served `default_project_id` the M3-frontend guard keys on, the
+`viewer` capability block (S5: `can_create_project`), and
+`default_project_readable` (whether the N=1 redirect target is reachable by this
+viewer — drives the deployment-directory empty state vs the land-in-corpus
+redirect).
+POST /api/projects — §22 S5 create-project (global-Owner only). The bot
+provisions a Gitea content repo and commits a project entry to `projects.yaml`;
+the registry mirror then upserts the `projects` + default `collections` rows
+(§22.2 keeps the registry the source of truth).
+GET  /api/projects/:id — one project's runtime config + optional theme overlay,
+gated behind the §22.5 read gate (404 for a non-member of a gated project).
+GET  /rfc/{slug}, /proposals/{n} — §22.10 server-side 308s onto the new
+`/p/<default>/…` routes (the SPA no longer owns these paths; nginx proxies them
+to the backend instead of serving index.html).
+"""
+from __future__ import annotations
+
+import json
+import re
+from typing import Any
+
+import yaml
+from fastapi import APIRouter, HTTPException, Request
+from fastapi.responses import RedirectResponse
+from pydantic import BaseModel
+
+from . import (
+    auth,
+    collections as collections_mod,
+    db,
+    projects as projects_mod,
+    registry as registry_mod,
+)
+from .bot import Bot
+from .config import Config
+from .gitea import Gitea, GiteaError
+
+# A project id is a slug (the §22.2 registry key + the `/p/<id>/` path segment).
+_SLUG_RE = re.compile(r"^[a-z0-9](?:[a-z0-9-]*[a-z0-9])?$")
+# A Gitea repo name: alphanumeric start, then alphanumerics / `-` / `_` / `.`.
+_REPO_RE = re.compile(r"^[A-Za-z0-9][A-Za-z0-9._-]*$")
+
+
+class CreateProjectBody(BaseModel):
+    project_id: str
+    name: str
+    type: str
+    visibility: str | None = None
+    content_repo: str | None = None
+
+
+def make_router(config: Config, gitea: Gitea, bot: Bot) -> APIRouter:
+    router = APIRouter()
+
+    @router.get("/api/deployment")
+    async def get_deployment(request: Request) -> dict[str, Any]:
+        viewer = auth.current_user(request)
+        dep = db.conn().execute(
+            "SELECT name, tagline FROM deployment WHERE id = 1"
+        ).fetchone()
+        # §22.5: enumerate only public + (member-)gated; unlisted is never listed.
+        visible = set(auth.visible_project_ids(viewer))
+        # §22 three-tier: `type` is a per-corpus field on the (default) collection
+        # now; surface the default collection's type for each project.
+        rows = db.conn().execute(
+            "SELECT id, name, visibility FROM projects "
+            "WHERE visibility != 'unlisted' ORDER BY name"
+        ).fetchall()
+        projects = [
+            {
+                "id": r["id"],
+                "name": r["name"],
+                "type": collections_mod.collection_type(
+                    collections_mod.default_collection_id(r["id"])
+                ),
+                "entry_noun": collections_mod.entry_noun(
+                    collections_mod.collection_type(
+                        collections_mod.default_collection_id(r["id"])
+                    )
+                ),
+                "visibility": r["visibility"],
+            }
+            for r in rows
+            if r["id"] in visible
+        ]
+        # §22 S5: the N=1 land-in-corpus redirect targets the default project, but
+        # only when this viewer can actually read it. A `gated` default (C3.2) or
+        # an absent default (C3.1, a deployment with no projects) is *not* a valid
+        # redirect target — the frontend then falls through to the deployment
+        # directory's role-aware empty state instead of bouncing into a 404.
+        default_id = projects_mod.resolved_default_id(config)
+        default_exists = db.conn().execute(
+            "SELECT 1 FROM projects WHERE id = ?", (default_id,)
+        ).fetchone() is not None
+        default_readable = default_exists and auth.can_read_project(viewer, default_id)
+        return {
+            "name": (dep["name"] if dep else "") or "",
+            "tagline": (dep["tagline"] if dep else "") or "",
+            # §22.10 / M3-frontend guard contract: which project the backend
+            # serves the corpus for (the default, until Plan B serves per
+            # project). The frontend renders corpus routes only for this id and
+            # shows a "content not yet served" placeholder for any other.
+            "default_project_id": default_id,
+            "default_project_readable": default_readable,
+            "projects": projects,
+            # §22 S5 (C3.1/C3.2): role-aware deployment-directory affordances.
+            "viewer": {"can_create_project": auth.can_create_project(viewer)},
+        }
+
+    @router.post("/api/projects")
+    async def create_project(body: CreateProjectBody, request: Request) -> dict[str, Any]:
+        # §22 S5 / §A.2 / §B.1: "+ New project" is a global-Owner action.
+        user = auth.require_contributor(request)
+        if not auth.can_create_project(user):
+            raise HTTPException(403, "Only a global Owner may create projects")
+        pid = body.project_id.strip().lower()
+        if not _SLUG_RE.match(pid) or pid == "default":
+            raise HTTPException(422, "project id must be a slug and not 'default'")
+        name = (body.name or "").strip()
+        if not name:
+            raise HTTPException(422, "project name is required")
+        if body.type not in registry_mod.VALID_TYPES:
+            raise HTTPException(422, f"invalid type {body.type!r}")
+        # A project is created visible by default — the point of standing one up
+        # is for it to be seen; an Owner narrows it afterwards (or picks gated).
+        visibility = (body.visibility or "public").strip()
+        if visibility not in registry_mod.VALID_VISIBILITY:
+            raise HTTPException(422, f"invalid visibility {visibility!r}")
+        if db.conn().execute("SELECT 1 FROM projects WHERE id = ?", (pid,)).fetchone():
+            raise HTTPException(409, f"project `{pid}` already exists")
+        content_repo = (body.content_repo or f"{pid}-content").strip()
+        if not _REPO_RE.match(content_repo):
+            raise HTTPException(422, f"invalid content repo name {content_repo!r}")
+        if await gitea.get_repo(config.gitea_org, content_repo) is not None:
+            raise HTTPException(409, f"repo `{content_repo}` already exists")
+
+        # Read the current registry, append the project, recompose. Reads live in
+        # gitea.py and may be called anywhere; the bot owns the write back.
+        read = await gitea.read_file(
+            config.gitea_org, config.registry_repo, "projects.yaml", ref="main"
+        )
+        if read is None:
+            raise HTTPException(409, "registry projects.yaml not found")
+        text, sha = read
+        try:
+            doc = yaml.safe_load(text) or {}
+        except yaml.YAMLError as e:
+            raise HTTPException(500, f"registry projects.yaml is not valid YAML: {e}")
+        if not isinstance(doc, dict):
+            raise HTTPException(500, "registry projects.yaml is malformed")
+        projects = doc.get("projects")
+        if not isinstance(projects, list):
+            projects = []
+        if any(isinstance(p, dict) and str(p.get("id") or "") == pid for p in projects):
+            raise HTTPException(409, f"project `{pid}` already in the registry")
+        projects.append(
+            {
+                "id": pid,
+                "name": name,
+                "type": body.type,
+                "content_repo": content_repo,
+                "visibility": visibility,
+            }
+        )
+        doc["projects"] = projects
+        new_text = yaml.safe_dump(doc, sort_keys=False)
+        readme_text = f"# {name}\n\nContent repository for project `{pid}`.\n"
+
+        try:
+            await bot.create_project(
+                user.as_actor(),
+                org=config.gitea_org,
+                registry_repo=config.registry_repo,
+                content_repo=content_repo,
+                project_id=pid,
+                projects_yaml_new=new_text,
+                projects_yaml_sha=sha,
+                readme_text=readme_text,
+            )
+        except GiteaError as e:
+            raise HTTPException(502, f"Gitea: {e.detail}")
+
+        # §22.2: re-read the registry so the new entry becomes projects +
+        # default-collection rows.
+        await registry_mod.refresh_registry(config, gitea)
+        row = db.conn().execute(
+            "SELECT id, name, visibility FROM projects WHERE id = ?", (pid,)
+        ).fetchone()
+        if row is None:
+            raise HTTPException(500, "project committed but not mirrored")
+        cid = collections_mod.default_collection_id(pid)
+        return {
+            "id": row["id"],
+            "name": row["name"],
+            "visibility": row["visibility"],
+            "type": collections_mod.collection_type(cid),
+        }
+
+    @router.get("/api/projects/{project_id}")
+    async def get_project(project_id: str, request: Request) -> dict[str, Any]:
+        viewer = auth.current_user(request)
+        # §22.5 read gate: a gated project 404s to a non-member (shape matches
+        # an unknown id). unlisted is readable by direct id.
+        auth.require_project_readable(viewer, project_id)
+        row = db.conn().execute(
+            "SELECT id, name, visibility, config_json FROM projects WHERE id = ?",
+            (project_id,),
+        ).fetchone()
+        if row is None:
+            raise HTTPException(status_code=404, detail="Not found")
+        try:
+            cfg = json.loads(row["config_json"] or "{}")
+        except (ValueError, TypeError):
+            cfg = {}
+        dep = db.conn().execute("SELECT tagline FROM deployment WHERE id = 1").fetchone()
+        # §22 three-tier: type + initial_state moved down to the (default)
+        # collection in migration 029.
+        cid = collections_mod.default_collection_id(row["id"])
+        return {
+            "id": row["id"],
+            "name": row["name"],
+            "tagline": (dep["tagline"] if dep else "") or "",
+            "type": collections_mod.collection_type(cid),
+            "entry_noun": collections_mod.entry_noun(collections_mod.collection_type(cid)),
+            "visibility": row["visibility"],
+            "initial_state": collections_mod.collection_initial_state(cid),
+            "theme": cfg.get("theme") or {},
+        }
+
+    # §22.10 / §5 — server-side 308s off the old corpus-root URLs onto the
+    # `/p/<default>/…` routes. 308 (not 301/302) preserves method + body and
+    # is permanent, so external "RFC-0001" links and bookmarks land correctly.
+    # nginx routes /rfc/ and /proposals/ to the backend so these are reached
+    # before the SPA's index.html fallback.
+    # §22 three-tier (S1): the canonical entry route now carries the collection
+    # segment /p/<project>/c/<collection>/…. The legacy roots redirect through
+    # the default project's default collection.
+    @router.get("/rfc/{slug}")
+    async def redirect_old_rfc(slug: str) -> RedirectResponse:
+        default_id = projects_mod.resolved_default_id(config)
+        cid = collections_mod.default_collection_id(default_id)
+        return RedirectResponse(url=f"/p/{default_id}/c/{cid}/e/{slug}", status_code=308)
+
+    @router.get("/rfc/{slug}/pr/{pr_number}")
+    async def redirect_old_rfc_pr(slug: str, pr_number: int) -> RedirectResponse:
+        default_id = projects_mod.resolved_default_id(config)
+        cid = collections_mod.default_collection_id(default_id)
+        return RedirectResponse(
+            url=f"/p/{default_id}/c/{cid}/e/{slug}/pr/{pr_number}", status_code=308
+        )
+
+    @router.get("/proposals/{pr_number}")
+    async def redirect_old_proposal(pr_number: int) -> RedirectResponse:
+        default_id = projects_mod.resolved_default_id(config)
+        cid = collections_mod.default_collection_id(default_id)
+        return RedirectResponse(url=f"/p/{default_id}/c/{cid}/proposals/{pr_number}", status_code=308)
+
+    return router

backend/app/api_discussion.py

@@ -84,7 +84,7 @@ def make_router() -> APIRouter:
     @router.get("/api/rfcs/{slug}/discussion/threads")
     async def list_discussion_threads(slug: str, request: Request) -> dict[str, Any]:
         viewer = auth.current_user(request)
-        _require_rfc_readable(slug)
+        _require_rfc_readable(slug, viewer)
         # Ensure the default whole-doc discussion thread exists. We mint
         # it on first read regardless of viewer (anonymous viewers can
         # trigger the creation — the row's `created_by` is null in that
@@ -115,7 +115,7 @@ def make_router() -> APIRouter:
         slug: str, body: DiscussionThreadCreateBody, request: Request
     ) -> dict[str, Any]:
         viewer = auth.require_contributor(request)
-        _require_rfc_readable(slug)
+        _require_rfc_readable(slug, viewer)
         # v0.16.0 (roadmap item #12): the per-RFC discussion is now a
         # gated surface. The platform-level `require_contributor` above
         # ensures the user is signed in + admin-granted; this layer
@@ -155,8 +155,8 @@ def make_router() -> APIRouter:
     async def get_discussion_thread_messages(
         slug: str, thread_id: int, request: Request
     ) -> dict[str, Any]:
-        _viewer = auth.current_user(request)
-        _require_rfc_readable(slug)
+        viewer = auth.current_user(request)
+        _require_rfc_readable(slug, viewer)
         thread = _require_discussion_thread(slug, thread_id)
         rows = db.conn().execute(
             """
@@ -193,7 +193,7 @@ def make_router() -> APIRouter:
         slug: str, thread_id: int, body: DiscussionMessageBody, request: Request
     ) -> dict[str, Any]:
         viewer = auth.require_contributor(request)
-        _require_rfc_readable(slug)
+        _require_rfc_readable(slug, viewer)
         # v0.16.0 (item #12): same per-RFC gate as create_discussion_thread.
         if not auth.can_discuss_rfc(viewer, slug):
             raise HTTPException(
@@ -218,7 +218,7 @@ def make_router() -> APIRouter:
         slug: str, thread_id: int, request: Request
     ) -> dict[str, Any]:
         viewer = auth.require_contributor(request)
-        rfc = _require_rfc_readable(slug)
+        rfc = _require_rfc_readable(slug, viewer)
         thread = _require_discussion_thread(slug, thread_id)
         if not _can_resolve(rfc, thread, viewer):
             raise HTTPException(
@@ -245,17 +245,24 @@ def make_router() -> APIRouter:
 # ---------------------------------------------------------------------------
 
 
-def _require_rfc_readable(slug: str):
-    """Per the v0.3.0 anonymous-read contract: any cached RFC is readable
-    by anyone. Withdrawn entries refuse reads of every shape — same rule
-    `_require_rfc_with_repo` in `api_branches.py` follows."""
+def _require_rfc_readable(slug: str, viewer):
+    """Per the v0.3.0 anonymous-read contract: any cached RFC in a *readable*
+    project is readable by anyone. The §22.5 visibility gate is subtractive on
+    top (§22.7): a gated project's entries 404 to non-members. Withdrawn
+    entries refuse reads of every shape — same rule `_require_rfc_with_repo`
+    in `api_branches.py` follows."""
     row = db.conn().execute(
-        "SELECT * FROM cached_rfcs WHERE slug = ?", (slug,)
+        "SELECT *, (SELECT c.project_id FROM collections c WHERE c.id = cached_rfcs.collection_id) AS project_id FROM cached_rfcs WHERE slug = ?", (slug,)
     ).fetchone()
     if row is None:
         raise HTTPException(404, "RFC not found")
+    auth.require_project_readable(viewer, row["project_id"])
     if row["state"] == "withdrawn":
         raise HTTPException(409, "RFC is withdrawn")
+    # §13.7: a retired entry is soft-deleted — refuse reads of every shape
+    # (a 404, not a 409: the entry is not surfaced anywhere a browser looks).
+    if row["state"] == "retired":
+        raise HTTPException(404, "RFC not found")
     return row
 
 
@@ -305,7 +312,7 @@ def _ensure_discussion_thread(slug: str, viewer) -> int:
 def _can_resolve(rfc, thread, viewer) -> bool:
     if viewer is None:
         return False
-    if viewer.role in ("owner", "admin"):
+    if auth.is_collection_superuser(viewer, rfc["collection_id"]):
         return True
     owners = json.loads(rfc["owners_json"] or "[]")
     arbiters = json.loads(rfc["arbiters_json"] or "[]")

backend/app/api_invitations.py

@@ -126,76 +126,22 @@ def make_router() -> APIRouter:
     @router.post("/api/rfcs/{slug}/invitations")
     async def create_invitation(slug: str, body: CreateInvitationBody, request: Request) -> dict[str, Any]:
         viewer = auth.require_contributor(request)
-        rfc = _require_rfc(slug)
+        rfc = _require_rfc(slug, viewer)
         if not auth.can_invite_to_rfc(viewer, slug):
             raise HTTPException(
                 403,
                 "Only the RFC's owner can invite collaborators",
             )
 
-        invitee_email = body.invitee_email.strip()
-        role_in_rfc = body.role_in_rfc
-
-        # Refuse re-inviting an email that already has a pending
-        # invitation on this RFC at the same role. Different-role
-        # re-invite is allowed (upgrade discussant → contributor)
-        # — the new row supersedes the old in the UI listing's
-        # natural ordering, and acceptance of either picks up the
-        # corresponding role.
-        existing = db.conn().execute(
-            """
-            SELECT id FROM rfc_invitations
-             WHERE rfc_slug = ? AND invitee_email = ? COLLATE NOCASE
-               AND role_in_rfc = ? AND status = 'pending'
-             LIMIT 1
-            """,
-            (slug, invitee_email, role_in_rfc),
-        ).fetchone()
-        if existing:
-            raise HTTPException(
-                409,
-                f"{invitee_email} already has a pending {role_in_rfc} invitation for this RFC",
-            )
-
-        token = _mint_token()
-        cur = db.conn().execute(
-            """
-            INSERT INTO rfc_invitations
-                (rfc_slug, inviter_user_id, invitee_email, role_in_rfc,
-                 token, expires_at)
-            VALUES (?, ?, ?, ?, ?, datetime('now', ?))
-            """,
-            (
-                slug,
-                viewer.user_id,
-                invitee_email,
-                role_in_rfc,
-                token,
-                f"+{INVITATION_TTL_DAYS} days",
-            ),
-        )
-        invitation_id = cur.lastrowid
-
-        # Send the email — synchronous. A send failure logs and
-        # returns; the row stays so the owner can recover via the
-        # listing (which carries the token for an out-of-band share).
-        _send_invitation_email(
-            to_address=invitee_email,
+        return issue_invitation(
+            slug=slug,
+            inviter_user_id=viewer.user_id,
             inviter_display=viewer.display_name or viewer.gitea_login or "An RFC owner",
+            invitee_email=body.invitee_email,
+            role_in_rfc=body.role_in_rfc,
             rfc_title=rfc["title"],
-            role_in_rfc=role_in_rfc,
-            token=token,
         )
 
-        return {
-            "id": invitation_id,
-            "rfc_slug": slug,
-            "invitee_email": invitee_email,
-            "role_in_rfc": role_in_rfc,
-            "status": "pending",
-            "token": token,
-        }
-
     # ---------------------------------------------------------------
     # GET /api/rfcs/<slug>/invitations
     # The owner's listing of every invitation on the RFC, regardless
@@ -205,7 +151,7 @@ def make_router() -> APIRouter:
     @router.get("/api/rfcs/{slug}/invitations")
     async def list_invitations(slug: str, request: Request) -> dict[str, Any]:
         viewer = auth.require_contributor(request)
-        _require_rfc(slug)
+        _require_rfc(slug, viewer)
         if not auth.can_invite_to_rfc(viewer, slug):
             raise HTTPException(
                 403,
@@ -261,7 +207,7 @@ def make_router() -> APIRouter:
     @router.post("/api/rfcs/{slug}/invitations/{invitation_id}/revoke")
     async def revoke_invitation(slug: str, invitation_id: int, request: Request) -> dict[str, Any]:
         viewer = auth.require_contributor(request)
-        _require_rfc(slug)
+        _require_rfc(slug, viewer)
         if not auth.can_invite_to_rfc(viewer, slug):
             raise HTTPException(
                 403,
@@ -427,15 +373,18 @@ def make_router() -> APIRouter:
 # ---------------------------------------------------------------------------
 
 
-def _require_rfc(slug: str):
+def _require_rfc(slug: str, viewer):
     """The invitation surface only operates on a known, non-withdrawn
     RFC. We refuse 404 on unknown and 409 on withdrawn — mirrors the
-    discussion endpoints' `_require_rfc_readable` shape."""
+    discussion endpoints' `_require_rfc_readable` shape. The §22.5
+    visibility gate is subtractive: a gated project's entries 404 to
+    non-members (§22.7)."""
     row = db.conn().execute(
-        "SELECT slug, title, state FROM cached_rfcs WHERE slug = ?", (slug,),
+        "SELECT slug, title, state, (SELECT c.project_id FROM collections c WHERE c.id = cached_rfcs.collection_id) AS project_id FROM cached_rfcs WHERE slug = ?", (slug,),
     ).fetchone()
     if row is None:
         raise HTTPException(404, "RFC not found")
+    auth.require_project_readable(viewer, row["project_id"])
     if row["state"] == "withdrawn":
         raise HTTPException(409, "RFC is withdrawn")
     return row
@@ -473,6 +422,78 @@ def _effective_status(row) -> str:
     return "expired" if is_past else "pending"
 
 
+def issue_invitation(
+    *,
+    slug: str,
+    inviter_user_id: int,
+    inviter_display: str,
+    invitee_email: str,
+    role_in_rfc: str,
+    rfc_title: str,
+) -> dict:
+    """Mint + persist + email one ``rfc_invitations`` row.
+
+    The single chokepoint for issuing an invitation: the owner's manual
+    `POST /api/rfcs/{slug}/invitations` endpoint and roadmap #28 Part 3's
+    accept path both route through here, so the dup-guard, token mint,
+    insert, and transactional email stay identical.
+
+    Refuses (409) re-inviting an email that already has a pending
+    invitation on this RFC at the same role. A different-role re-invite is
+    allowed (the discussant → contributor upgrade) — the new row
+    supersedes the old in the listing's natural ordering, and acceptance
+    of either picks up the corresponding role.
+
+    Returns the new row's dict (including the raw token, for the owner's
+    out-of-band share / the caller's record-keeping). A send failure logs
+    and returns; the row stays so the owner can recover via the listing.
+    """
+    invitee_email = invitee_email.strip()
+    existing = db.conn().execute(
+        """
+        SELECT id FROM rfc_invitations
+         WHERE rfc_slug = ? AND invitee_email = ? COLLATE NOCASE
+           AND role_in_rfc = ? AND status = 'pending'
+         LIMIT 1
+        """,
+        (slug, invitee_email, role_in_rfc),
+    ).fetchone()
+    if existing:
+        raise HTTPException(
+            409,
+            f"{invitee_email} already has a pending {role_in_rfc} invitation for this RFC",
+        )
+
+    token = _mint_token()
+    cur = db.conn().execute(
+        """
+        INSERT INTO rfc_invitations
+            (rfc_slug, inviter_user_id, invitee_email, role_in_rfc,
+             token, expires_at)
+        VALUES (?, ?, ?, ?, ?, datetime('now', ?))
+        """,
+        (slug, inviter_user_id, invitee_email, role_in_rfc, token, f"+{INVITATION_TTL_DAYS} days"),
+    )
+    invitation_id = cur.lastrowid
+
+    _send_invitation_email(
+        to_address=invitee_email,
+        inviter_display=inviter_display,
+        rfc_title=rfc_title,
+        role_in_rfc=role_in_rfc,
+        token=token,
+    )
+
+    return {
+        "id": invitation_id,
+        "rfc_slug": slug,
+        "invitee_email": invitee_email,
+        "role_in_rfc": role_in_rfc,
+        "status": "pending",
+        "token": token,
+    }
+
+
 def _mint_token() -> str:
     """A 256-bit URL-safe token. The token shape is opaque to the
     consumer; the email link encodes it as a query param."""

backend/app/api_join_requests.py

@@ -0,0 +1,311 @@
+"""§22.8 S6 — request-to-join a scope + the cross-collection inbox.
+
+A gated project or collection is invisible to non-members (§22.5), so joining is
+by invite (an Owner grants directly — `api_memberships.py`) *or* by request: a
+user who knows a scope exists asks to join it, naming a desired role. This module
+is the request side:
+
+  * ``GET  /api/scopes/{scope_type}/{scope_id}/join-target`` — what the join
+    form needs (the scope's name, the viewer's eligibility + whether they already
+    have a pending ask + their current role).
+  * ``POST /api/scopes/{scope_type}/{scope_id}/join-requests`` — submit the ask
+    (desired role + optional message); lands a row + one §15 notification per
+    Owner across the scope's subtree (the cross-collection inbox, §22.11).
+  * ``POST /api/scopes/{scope_type}/{scope_id}/join-requests/{id}/accept`` —
+    Owner: accept, which writes the `memberships` row via ``memberships.grant``
+    (the §22.8 "accepting writes the membership row"), then notifies the requester.
+  * ``POST /api/scopes/{scope_type}/{scope_id}/join-requests/{id}/decline`` —
+    Owner: decline; the request closes and the requester is notified.
+
+Mirrors ``api_contributions.py`` (the per-RFC contribute-request flow) but at the
+scope grain: the target is a ``(scope_type, scope_id)`` pair drawn from the
+``memberships`` scope vocabulary (minus ``global`` — a deployment isn't a thing
+one discovers and joins), and accept grants a scope role rather than minting an
+RFC invitation.
+
+The request POST deliberately does **not** require the scope be *readable*: the
+whole point of request-to-join is to ask into a *gated* scope you were told about
+but cannot see (§22.8). It is gated only on "you're signed in, granted, and not
+already a member". Accept/decline are gated on Owner reach over the scope
+(``auth.can_invite_at_project`` / ``auth.can_invite_at_collection``).
+"""
+from __future__ import annotations
+
+import sqlite3
+from typing import Any
+
+from fastapi import APIRouter, HTTPException, Request
+from pydantic import BaseModel, Field
+
+from . import (
+    auth,
+    collections as collections_mod,
+    db,
+    memberships as memberships_mod,
+    notify,
+)
+
+_MESSAGE_MAX = 4000
+
+
+class JoinRequestBody(BaseModel):
+    role: str
+    message: str | None = Field(default=None, max_length=_MESSAGE_MAX)
+
+
+class DecideBody(BaseModel):
+    # On accept, the Owner may grant a role narrower than the one requested; a
+    # missing value grants exactly the requested role.
+    role: str | None = None
+
+
+def _project_name(project_id: str) -> str | None:
+    row = db.conn().execute(
+        "SELECT name FROM projects WHERE id = ?", (project_id,)
+    ).fetchone()
+    return row["name"] if row and row["name"] else None
+
+
+def _resolve_scope(scope_type: str, scope_id: str) -> dict[str, Any]:
+    """Resolve a `(scope_type, scope_id)` target to its display facts, or 404 if
+    it doesn't exist. Returns `{project_id, scope_name, project_name}`. The
+    `scope_type` itself must be one of the join-able scopes."""
+    if scope_type == "project":
+        row = db.conn().execute(
+            "SELECT id, name FROM projects WHERE id = ?", (scope_id,)
+        ).fetchone()
+        if row is None:
+            raise HTTPException(404, "Not found")
+        name = row["name"] or scope_id
+        return {"project_id": scope_id, "scope_name": name, "project_name": name}
+    if scope_type == "collection":
+        col = collections_mod.get_collection(scope_id)
+        if col is None:
+            raise HTTPException(404, "Not found")
+        pid = col["project_id"]
+        return {
+            "project_id": pid,
+            "scope_name": col.get("name") or scope_id,
+            "project_name": _project_name(pid),
+        }
+    raise HTTPException(404, "Not found")
+
+
+def _require_join_owner(viewer, scope_type: str, scope_id: str) -> None:
+    """The accept/decline gate: an Owner whose reach covers the scope (§22.8 'the
+    scope's Owners across the subtree'). Reuses the S4 invite gates."""
+    ok = (
+        auth.can_invite_at_collection(viewer, scope_id)
+        if scope_type == "collection"
+        else auth.can_invite_at_project(viewer, scope_id)
+    )
+    if not ok:
+        raise HTTPException(403, "Only an Owner of this scope can act on join requests")
+
+
+def _require_request(scope_type: str, scope_id: str, request_id: int):
+    row = db.conn().execute(
+        """
+        SELECT id, scope_type, scope_id, requester_user_id, requested_role,
+               message, status
+          FROM join_requests
+         WHERE id = ? AND scope_type = ? AND scope_id = ?
+        """,
+        (request_id, scope_type, scope_id),
+    ).fetchone()
+    if row is None:
+        raise HTTPException(404, "Join request not found")
+    return row
+
+
+def make_router() -> APIRouter:
+    router = APIRouter()
+
+    # ---------------------------------------------------------------
+    # GET — what the join form needs to render + gate itself.
+    # ---------------------------------------------------------------
+
+    @router.get("/api/scopes/{scope_type}/{scope_id}/join-target")
+    async def join_target(scope_type: str, scope_id: str, request: Request) -> dict[str, Any]:
+        facts = _resolve_scope(scope_type, scope_id)
+        viewer = auth.current_user(request)
+
+        eligible = True
+        reason: str | None = None
+        already_requested = False
+        current_role = auth.effective_role_at_scope(viewer, scope_type, scope_id)
+
+        if viewer is None:
+            eligible, reason = False, "Sign in to request to join."
+        elif viewer.permission_state != "granted":
+            eligible, reason = False, "Your beta access request is in review."
+        elif current_role is not None:
+            eligible, reason = False, f"You already hold {('Owner' if current_role == 'owner' else 'RFC Contributor')} here."
+        else:
+            already_requested = bool(
+                db.conn().execute(
+                    """
+                    SELECT 1 FROM join_requests
+                     WHERE scope_type = ? AND scope_id = ? AND requester_user_id = ?
+                       AND status = 'pending' LIMIT 1
+                    """,
+                    (scope_type, scope_id, viewer.user_id),
+                ).fetchone()
+            )
+
+        return {
+            "scope_type": scope_type,
+            "scope_id": scope_id,
+            "name": facts["scope_name"],
+            "project_id": facts["project_id"],
+            "eligible": eligible and not already_requested,
+            "reason": reason,
+            "already_requested": already_requested,
+            "current_role": current_role,
+        }
+
+    # ---------------------------------------------------------------
+    # POST — submit a request to join.
+    # ---------------------------------------------------------------
+
+    @router.post("/api/scopes/{scope_type}/{scope_id}/join-requests")
+    async def create_join_request(
+        scope_type: str, scope_id: str, body: JoinRequestBody, request: Request
+    ) -> dict[str, Any]:
+        viewer = auth.require_contributor(request)
+        facts = _resolve_scope(scope_type, scope_id)
+
+        role = (body.role or "").strip().lower()
+        if role not in memberships_mod.VALID_ROLES:
+            raise HTTPException(422, f"invalid role {body.role!r}")
+
+        # Already a member of the scope (at this or a broader grain)? Then there
+        # is nothing to request — a clear 409 rather than a useless self-request.
+        if auth.effective_role_at_scope(viewer, scope_type, scope_id) is not None:
+            raise HTTPException(409, "You already hold a role in this scope.")
+
+        message = (body.message or "").strip() or None
+
+        try:
+            cur = db.conn().execute(
+                """
+                INSERT INTO join_requests
+                    (scope_type, scope_id, requester_user_id, requested_role, message)
+                VALUES (?, ?, ?, ?, ?)
+                """,
+                (scope_type, scope_id, viewer.user_id, role, message),
+            )
+        except sqlite3.IntegrityError:
+            # The partial unique index — one open request per (scope, user).
+            raise HTTPException(409, "You already have a pending request to join this scope.")
+        request_id = cur.lastrowid
+
+        # One actionable notification per Owner across the subtree; stamp the
+        # first onto the row as the inbox-action handle (any Owner may act).
+        notif_ids = notify.fan_out_join_request(
+            scope_type=scope_type,
+            scope_id=scope_id,
+            scope_name=facts["scope_name"],
+            project_id=facts["project_id"],
+            project_name=facts["project_name"],
+            requester_user_id=viewer.user_id,
+            request_id=request_id,
+            requested_role=role,
+            message=message,
+        )
+        if notif_ids:
+            db.conn().execute(
+                "UPDATE join_requests SET notification_id = ? WHERE id = ?",
+                (notif_ids[0], request_id),
+            )
+
+        return {"id": request_id, "scope_type": scope_type, "scope_id": scope_id, "status": "pending"}
+
+    # ---------------------------------------------------------------
+    # POST — Owner accepts → write the membership row.
+    # ---------------------------------------------------------------
+
+    @router.post("/api/scopes/{scope_type}/{scope_id}/join-requests/{request_id}/accept")
+    async def accept_join_request(
+        scope_type: str, scope_id: str, request_id: int, body: DecideBody, request: Request
+    ) -> dict[str, Any]:
+        viewer = auth.require_contributor(request)
+        facts = _resolve_scope(scope_type, scope_id)
+        _require_join_owner(viewer, scope_type, scope_id)
+
+        req = _require_request(scope_type, scope_id, request_id)
+        if req["status"] != "pending":
+            raise HTTPException(409, f"This request was already {req['status']}.")
+
+        # The Owner may narrow the requested role on accept; default to what was
+        # asked for. (Both are within the Owner's grant reach at this scope.)
+        granted_role = (body.role or req["requested_role"] or "").strip().lower()
+        if granted_role not in memberships_mod.VALID_ROLES:
+            raise HTTPException(422, f"invalid role {body.role!r}")
+
+        memberships_mod.grant(
+            scope_type=scope_type,
+            scope_id=scope_id,
+            user_id=req["requester_user_id"],
+            role=granted_role,
+            granted_by=viewer.user_id,
+        )
+        db.conn().execute(
+            """
+            UPDATE join_requests
+               SET status = 'accepted', decided_at = datetime('now'),
+                   decided_by_user_id = ?, granted_role = ?
+             WHERE id = ?
+            """,
+            (viewer.user_id, granted_role, request_id),
+        )
+        notify.notify_join_decided(
+            requester_user_id=req["requester_user_id"],
+            decider_user_id=viewer.user_id,
+            request_id=request_id,
+            scope_type=scope_type,
+            scope_id=scope_id,
+            scope_name=facts["scope_name"],
+            granted_role=granted_role,
+            accepted=True,
+        )
+        return {"ok": True, "status": "accepted", "granted_role": granted_role}
+
+    # ---------------------------------------------------------------
+    # POST — Owner declines.
+    # ---------------------------------------------------------------
+
+    @router.post("/api/scopes/{scope_type}/{scope_id}/join-requests/{request_id}/decline")
+    async def decline_join_request(
+        scope_type: str, scope_id: str, request_id: int, request: Request
+    ) -> dict[str, Any]:
+        viewer = auth.require_contributor(request)
+        facts = _resolve_scope(scope_type, scope_id)
+        _require_join_owner(viewer, scope_type, scope_id)
+
+        req = _require_request(scope_type, scope_id, request_id)
+        if req["status"] != "pending":
+            raise HTTPException(409, f"This request was already {req['status']}.")
+
+        db.conn().execute(
+            """
+            UPDATE join_requests
+               SET status = 'declined', decided_at = datetime('now'),
+                   decided_by_user_id = ?
+             WHERE id = ?
+            """,
+            (viewer.user_id, request_id),
+        )
+        notify.notify_join_decided(
+            requester_user_id=req["requester_user_id"],
+            decider_user_id=viewer.user_id,
+            request_id=request_id,
+            scope_type=scope_type,
+            scope_id=scope_id,
+            scope_name=facts["scope_name"],
+            granted_role=None,
+            accepted=False,
+        )
+        return {"ok": True, "status": "declined"}
+
+    return router

backend/app/api_memberships.py

@@ -0,0 +1,157 @@
+"""§22 S4 (C.2) — the scope-role invitation surface.
+
+An Owner grants `{owner, contributor}` at a scope their reach covers — the
+project, or a single collection within it — to an existing account, looked up
+by email. The grant writes a `memberships` row immediately and §15-notifies
+the grantee (there is no accept round-trip; the C.2 scenarios name an existing
+user and write the row directly). Endpoints:
+
+  GET    /api/projects/:pid/members                 — list the project subtree's grants
+  POST   /api/projects/:pid/members                 — grant at project scope, or
+                                                      (with collection_id) at one collection
+  DELETE /api/projects/:pid/members/:user_id         — revoke (optionally ?collection_id=)
+
+The single POST keys on the optional `collection_id` so the invite UI's one
+control (role picker + scope picker) maps to one endpoint:
+
+  * no `collection_id`  → project-scope grant; gate `can_invite_at_project`.
+  * with `collection_id` → collection-scope grant; gate `can_invite_at_collection`.
+
+There is deliberately no "grant at parent, exclude a child" parameter (C.2.5):
+the only knobs are role ∈ {owner, contributor} and scope ∈ {project, one
+collection}. Reach is bounded by the inviter's own Owner reach (C.2.3): a
+collection Owner who is nothing more is refused the project-scope POST.
+"""
+from __future__ import annotations
+
+from typing import Any
+
+from fastapi import APIRouter, HTTPException, Request
+from pydantic import BaseModel
+
+from . import (
+    auth,
+    collections as collections_mod,
+    db,
+    memberships as memberships_mod,
+    notify,
+)
+
+
+class GrantBody(BaseModel):
+    email: str
+    role: str
+    collection_id: str | None = None
+
+
+def _project_name(project_id: str) -> str | None:
+    row = db.conn().execute(
+        "SELECT name FROM projects WHERE id = ?", (project_id,)
+    ).fetchone()
+    return row["name"] if row and row["name"] else None
+
+
+def make_router() -> APIRouter:
+    router = APIRouter()
+
+    @router.get("/api/projects/{project_id}/members")
+    async def list_members(project_id: str, request: Request) -> dict[str, Any]:
+        user = auth.require_contributor(request)
+        auth.require_project_readable(user, project_id)
+        # The full subtree listing is a project-Owner view; a collection-only
+        # Owner manages membership through the collection-scoped POST/DELETE.
+        if not auth.can_invite_at_project(user, project_id):
+            raise HTTPException(403, "You may not manage membership in this project")
+        return {"items": memberships_mod.list_for_project(project_id)}
+
+    @router.post("/api/projects/{project_id}/members")
+    async def grant_member(
+        project_id: str, body: GrantBody, request: Request
+    ) -> dict[str, Any]:
+        user = auth.require_contributor(request)
+        auth.require_project_readable(user, project_id)
+
+        role = (body.role or "").strip().lower()
+        if role not in memberships_mod.VALID_ROLES:
+            raise HTTPException(422, f"invalid role {body.role!r}")
+
+        cid = (body.collection_id or "").strip() or None
+        if cid is not None:
+            # Collection-scope grant — bounded by Owner reach over that collection.
+            col = collections_mod.get_collection(cid)
+            if col is None or col["project_id"] != project_id:
+                raise HTTPException(404, "Not found")
+            if not auth.can_invite_at_collection(user, cid):
+                raise HTTPException(403, "You may not manage membership in this collection")
+            scope_type, scope_id = "collection", cid
+        else:
+            # Project-scope grant — bounded by Owner reach over the project.
+            if not auth.can_invite_at_project(user, project_id):
+                raise HTTPException(403, "You may not manage membership in this project")
+            scope_type, scope_id = "project", project_id
+
+        grantee = memberships_mod.user_by_email(body.email)
+        if grantee is None:
+            raise HTTPException(
+                404,
+                "No account with that email — the invitee must sign in to the "
+                "deployment before they can be granted a role",
+            )
+
+        memberships_mod.grant(
+            scope_type=scope_type,
+            scope_id=scope_id,
+            user_id=grantee["id"],
+            role=role,
+            granted_by=user.user_id,
+        )
+
+        # §15 (C.2): name the project and role to the grantee.
+        col_name = None
+        if scope_type == "collection":
+            col = collections_mod.get_collection(scope_id)
+            col_name = (col.get("name") if col else None) or scope_id
+        notify.notify_scope_role_granted(
+            recipient_user_id=grantee["id"],
+            granter_user_id=user.user_id,
+            scope_type=scope_type,
+            scope_id=scope_id,
+            role=role,
+            project_id=project_id,
+            project_name=_project_name(project_id),
+            collection_name=col_name,
+        )
+
+        return {
+            "scope_type": scope_type,
+            "scope_id": scope_id,
+            "user_id": grantee["id"],
+            "role": role,
+            "pending": grantee["permission_state"] != "granted",
+        }
+
+    @router.delete("/api/projects/{project_id}/members/{user_id}")
+    async def revoke_member(
+        project_id: str, user_id: int, request: Request
+    ) -> dict[str, Any]:
+        user = auth.require_contributor(request)
+        auth.require_project_readable(user, project_id)
+        cid = (request.query_params.get("collection_id") or "").strip() or None
+        if cid is not None:
+            col = collections_mod.get_collection(cid)
+            if col is None or col["project_id"] != project_id:
+                raise HTTPException(404, "Not found")
+            if not auth.can_invite_at_collection(user, cid):
+                raise HTTPException(403, "You may not manage membership in this collection")
+            removed = memberships_mod.revoke(
+                scope_type="collection", scope_id=cid, user_id=user_id
+            )
+        else:
+            if not auth.can_invite_at_project(user, project_id):
+                raise HTTPException(403, "You may not manage membership in this project")
+            removed = memberships_mod.revoke(
+                scope_type="project", scope_id=project_id, user_id=user_id
+            )
+        return {"removed": removed}
+
+    return router

backend/app/api_notifications.py

@@ -213,14 +213,16 @@ def make_router(config: Config) -> APIRouter:
     @router.post("/api/rfcs/{slug}/watch")
     async def set_watch(slug: str, body: WatchBody, request: Request) -> dict[str, Any]:
         viewer = auth.require_user(request)
-        rfc = db.conn().execute("SELECT slug FROM cached_rfcs WHERE slug = ?", (slug,)).fetchone()
+        rfc = db.conn().execute("SELECT (SELECT c.project_id FROM collections c WHERE c.id = cached_rfcs.collection_id) AS project_id FROM cached_rfcs WHERE slug = ?", (slug,)).fetchone()
         if rfc is None:
             raise HTTPException(404, "RFC not found")
+        # §22.5 visibility gate (subtractive): gated → 404 to non-members.
+        auth.require_project_readable(viewer, rfc["project_id"])
         db.conn().execute(
             """
             INSERT INTO watches (user_id, rfc_slug, state, set_by, set_at, last_participation_at)
             VALUES (?, ?, ?, 'explicit', datetime('now'), datetime('now'))
-            ON CONFLICT(user_id, rfc_slug) DO UPDATE SET
+            ON CONFLICT(collection_id, user_id, rfc_slug) DO UPDATE SET
                 state = excluded.state,
                 set_by = 'explicit',
                 set_at = excluded.set_at
@@ -557,7 +559,26 @@ def make_router(config: Config) -> APIRouter:
         # stays unauthenticated for dev (the v1 contract).
         import os as _os
         expected = _os.environ.get("WEBHOOK_EMAIL_BOUNCE_SECRET", "").strip()
-        if expected:
+        # v0.25.0 (audit 0026 M5): fail closed. An unset secret used to
+        # leave this endpoint fully unauthenticated — anyone could suppress
+        # any user's mail by POSTing their address (email_opt_out_all flip
+        # below). Now an unset secret DISABLES the endpoint (503) instead
+        # of opening it. A dev that genuinely wants it open opts in
+        # explicitly with RFC_APP_INSECURE_BOUNCE_WEBHOOK=1, mirroring the
+        # RFC_APP_INSECURE_WEBHOOKS dev-bypass on the Gitea hook.
+        if not expected:
+            if _os.environ.get("RFC_APP_INSECURE_BOUNCE_WEBHOOK", "").strip() == "1":
+                log.warning(
+                    "email-bounce webhook running UNAUTHENTICATED "
+                    "(RFC_APP_INSECURE_BOUNCE_WEBHOOK=1) — never set this in production"
+                )
+            else:
+                log.error(
+                    "email-bounce webhook refused: WEBHOOK_EMAIL_BOUNCE_SECRET is unset "
+                    "(set the secret to enable, or RFC_APP_INSECURE_BOUNCE_WEBHOOK=1 for dev)"
+                )
+                raise HTTPException(503, "Bounce webhook not configured")
+        else:
             received = request.headers.get("X-Webhook-Secret", "")
             import hmac as _hmac
             if not received or not _hmac.compare_digest(expected, received):

backend/app/api_prs.py

@@ -23,7 +23,7 @@ from typing import Any
 from fastapi import APIRouter, HTTPException, Request
 from pydantic import BaseModel, Field
 
-from . import auth, cache, chat as chat_layer, db, entry as entry_mod, funder, models_resolver, rfc_links
+from . import auth, cache, chat as chat_layer, db, entry as entry_mod, funder, models_resolver, projects as projects_mod, rfc_links
 from .bot import Bot
 from .config import Config
 from .gitea import Gitea, GiteaError
@@ -85,7 +85,7 @@ def make_router(
     @router.post("/api/rfcs/{slug}/branches/{branch:path}/pr-draft")
     async def draft_pr_text(slug: str, branch: str, request: Request) -> dict[str, Any]:
         viewer = auth.require_contributor(request)
-        rfc = _require_active_rfc(slug)
+        rfc = _require_active_rfc(slug, viewer)
         owner, repo = _owner_repo(rfc)
         path = _file_path_for(rfc)
         if not _branch_has_commits_ahead(slug, branch):
@@ -128,7 +128,7 @@ def make_router(
                 403,
                 "This RFC's owner has not invited you to contribute PRs",
             )
-        rfc = _require_active_rfc(slug)
+        rfc = _require_active_rfc(slug, viewer)
         if branch == "main":
             raise HTTPException(409, "PRs open from non-main branches")
         owner, repo = _owner_repo(rfc)
@@ -153,7 +153,7 @@ def make_router(
             """
             INSERT INTO branch_visibility (rfc_slug, branch_name, read_public, contribute_mode)
             VALUES (?, ?, 1, 'just-me')
-            ON CONFLICT(rfc_slug, branch_name) DO UPDATE SET read_public = 1
+            ON CONFLICT(collection_id, rfc_slug, branch_name) DO UPDATE SET read_public = 1
             """,
             (slug, branch),
         )
@@ -189,7 +189,7 @@ def make_router(
                 """
                 INSERT INTO proposed_use_cases (scope, rfc_slug, pr_number, use_case)
                 VALUES ('pr', ?, ?, ?)
-                ON CONFLICT(scope, pr_number) DO UPDATE SET use_case = excluded.use_case
+                ON CONFLICT(collection_id, scope, pr_number) DO UPDATE SET use_case = excluded.use_case
                 """,
                 (slug, pr["number"], use_case),
             )
@@ -207,7 +207,7 @@ def make_router(
     @router.get("/api/rfcs/{slug}/prs/{pr_number}")
     async def get_pr(slug: str, pr_number: int, request: Request) -> dict[str, Any]:
         viewer = auth.current_user(request)
-        rfc = _require_active_rfc(slug)
+        rfc = _require_active_rfc(slug, viewer)
         pr_row = _require_pr(slug, pr_number)
         owner, repo = _owner_repo(rfc)
         path = _file_path_for(rfc)
@@ -373,7 +373,7 @@ def make_router(
     @router.post("/api/rfcs/{slug}/prs/{pr_number}/seen")
     async def advance_seen(slug: str, pr_number: int, body: PRSeenBody, request: Request) -> dict[str, Any]:
         viewer = auth.require_contributor(request)
-        _require_active_rfc(slug)
+        _require_active_rfc(slug, viewer)
         _require_pr(slug, pr_number)
         # Take the max of stored and incoming for both cursors so a
         # stale tab firing a seen-cursor advance after a fresher tab
@@ -398,7 +398,7 @@ def make_router(
             INSERT INTO pr_seen
                 (user_id, rfc_slug, pr_number, last_seen_commit_sha, last_seen_message_id, seen_at)
             VALUES (?, ?, ?, ?, ?, datetime('now'))
-            ON CONFLICT(user_id, rfc_slug, pr_number) DO UPDATE SET
+            ON CONFLICT(collection_id, user_id, rfc_slug, pr_number) DO UPDATE SET
                 last_seen_commit_sha = excluded.last_seen_commit_sha,
                 last_seen_message_id = excluded.last_seen_message_id,
                 seen_at = excluded.seen_at
@@ -420,7 +420,7 @@ def make_router(
     @router.post("/api/rfcs/{slug}/prs/{pr_number}/review")
     async def post_review_thread(slug: str, pr_number: int, body: PRReviewBody, request: Request) -> dict[str, Any]:
         viewer = auth.require_contributor(request)
-        _require_active_rfc(slug)
+        _require_active_rfc(slug, viewer)
         pr_row = _require_pr(slug, pr_number)
         head_branch = pr_row["head_branch"]
         cur = db.conn().execute(
@@ -447,7 +447,7 @@ def make_router(
     @router.post("/api/rfcs/{slug}/prs/{pr_number}/merge")
     async def merge_pr(slug: str, pr_number: int, request: Request) -> dict[str, Any]:
         viewer = auth.require_contributor(request)
-        rfc = _require_active_rfc(slug)
+        rfc = _require_active_rfc(slug, viewer)
         pr_row = _require_pr(slug, pr_number)
         if not _can_merge(rfc, viewer):
             raise HTTPException(403, "Only arbiters, RFC owners, and app admins/owners may merge")
@@ -479,7 +479,7 @@ def make_router(
     @router.post("/api/rfcs/{slug}/prs/{pr_number}/withdraw")
     async def withdraw_pr(slug: str, pr_number: int, request: Request) -> dict[str, Any]:
         viewer = auth.require_contributor(request)
-        rfc = _require_active_rfc(slug)
+        rfc = _require_active_rfc(slug, viewer)
         pr_row = _require_pr(slug, pr_number)
         if not _can_withdraw(rfc, pr_row, viewer):
             raise HTTPException(403, "Only the contributor or an RFC owner/arbiter (or app admin/owner) may withdraw")
@@ -510,7 +510,7 @@ def make_router(
         slug: str, pr_number: int, body: PRDescriptionBody, request: Request
     ) -> dict[str, Any]:
         viewer = auth.require_contributor(request)
-        rfc = _require_active_rfc(slug)
+        rfc = _require_active_rfc(slug, viewer)
         pr_row = _require_pr(slug, pr_number)
         if not _can_edit_pr_text(rfc, pr_row, viewer):
             raise HTTPException(403, "Only the contributor or an RFC owner/arbiter (or admin/owner) may edit")
@@ -535,7 +535,7 @@ def make_router(
     @router.post("/api/rfcs/{slug}/prs/{pr_number}/resolution-branch")
     async def start_resolution_branch(slug: str, pr_number: int, request: Request) -> dict[str, Any]:
         viewer = auth.require_contributor(request)
-        rfc = _require_active_rfc(slug)
+        rfc = _require_active_rfc(slug, viewer)
         pr_row = _require_pr(slug, pr_number)
         if pr_row["state"] != "open":
             raise HTTPException(409, f"PR is {pr_row['state']}, not open")
@@ -603,7 +603,7 @@ def make_router(
             repo=repo,
             slug=slug,
             file_path=_file_path_for(rfc),
-            is_super_draft=_is_super_draft(rfc),
+            is_super_draft=_is_meta_resident(rfc),
             original_branch=original_branch,
             resolution_branch=resolution_branch,
         )
@@ -661,42 +661,49 @@ def make_router(
     # Helpers (closures over config/gitea/etc.)
     # ------------------------------------------------------------------
 
-    def _require_rfc(slug: str):
-        row = db.conn().execute("SELECT * FROM cached_rfcs WHERE slug = ?", (slug,)).fetchone()
+    def _require_rfc(slug: str, viewer):
+        row = db.conn().execute("SELECT *, (SELECT c.project_id FROM collections c WHERE c.id = cached_rfcs.collection_id) AS project_id FROM cached_rfcs WHERE slug = ?", (slug,)).fetchone()
         if row is None:
             raise HTTPException(404, "RFC not found")
+        # §22.5 visibility gate (subtractive, §22.7) — even §11.3 "PRs always
+        # public" yields to a gated project: non-members get 404.
+        auth.require_project_readable(viewer, row["project_id"])
         return row
 
-    def _require_active_rfc(slug: str):
+    def _require_active_rfc(slug: str, viewer):
         """Used by the §10 PR-flow read and write paths. Per §17's routing-
         collapse rule, a super-draft RFC also routes here — its body-edit
         PRs are meta-repo PRs with pr_kind='meta_body_edit', but the API
-        surface is identical."""
-        row = _require_rfc(slug)
+        surface is identical. Under the meta-only topology (§1) an active
+        RFC is meta-resident too (repo is null) — that is normal, not an
+        error, so there is no per-RFC-repo precondition."""
+        row = _require_rfc(slug, viewer)
         if row["state"] not in ("active", "super-draft"):
             raise HTTPException(409, f"RFC is {row['state']}")
-        if row["state"] == "active" and not row["repo"]:
-            raise HTTPException(409, "RFC has no repo")
         return row
 
-    def _is_super_draft(rfc) -> bool:
-        return rfc["state"] == "super-draft"
+    def _is_meta_resident(rfc) -> bool:
+        """Meta-only topology (§1): an entry lives in the meta repo's
+        `rfcs/<slug>.md` (super-draft or active-in-place) unless it carries
+        a legacy per-RFC `repo:` — which nothing does after the RFC-0001
+        fold-back (§13.6). Drives the body/path/repo dispatch below."""
+        return not rfc["repo"]
 
     def _owner_repo(rfc) -> tuple[str, str]:
-        if _is_super_draft(rfc):
-            return config.gitea_org, config.meta_repo
+        if _is_meta_resident(rfc):
+            return config.gitea_org, (projects_mod.default_content_repo(config) or "")
         owner, repo = rfc["repo"].split("/", 1)
         return owner, repo
 
     def _file_path_for(rfc) -> str:
-        if _is_super_draft(rfc):
+        if _is_meta_resident(rfc):
             return f"rfcs/{rfc['slug']}.md"
         return RFC_FILE_PATH
 
     def _extract_body(rfc, file_contents: str) -> str:
-        """For super-draft entries the file on disk is the full
+        """For meta-resident entries the file on disk is the full
         frontmatter+body envelope; the editable body is entry.body."""
-        if not _is_super_draft(rfc):
+        if not _is_meta_resident(rfc):
             return file_contents
         try:
             entry = entry_mod.parse(file_contents)
@@ -760,7 +767,7 @@ def make_router(
         return row["original_pr_number"] if row else None
 
     async def _refresh_after_pr_write(rfc) -> None:
-        if _is_super_draft(rfc):
+        if _is_meta_resident(rfc):
             await cache.refresh_meta_repo(config, gitea)
             await cache.refresh_meta_branches(config, gitea)
             await cache.refresh_meta_pulls(config, gitea)
@@ -776,10 +783,10 @@ def make_router(
 
 
 def _can_merge(rfc, viewer) -> bool:
-    """§6.1 admin/owner OR §6.3 RFC owners/arbiters."""
+    """§6.1 admin/owner or §22.6 project_admin OR §6.3 RFC owners/arbiters."""
     if viewer is None:
         return False
-    if viewer.role in ("owner", "admin"):
+    if auth.is_collection_superuser(viewer, rfc["collection_id"]):
         return True
     owners = json.loads(rfc["owners_json"] or "[]")
     arbiters = json.loads(rfc["arbiters_json"] or "[]")

backend/app/auth.py

@@ -16,9 +16,11 @@ from typing import Any
 import httpx
 from fastapi import HTTPException, Request
 
+from . import collections as collections_mod
 from . import db
 from .bot import Actor
 from .config import Config
+from .projects import DEFAULT_PROJECT_ID
 
 
 @dataclass
@@ -290,6 +292,471 @@ def require_admin(request: Request) -> SessionUser:
     return user
 
 
+# ===========================================================================
+# §22.6 / §22.7 — project-scoped authorization (the multi-project middle tier).
+#
+# A deployment hosts N projects (§22). Authorization for an action on an RFC is
+# the *most-permissive union* of three tiers — the actor's deployment role
+# (§6.1), their project role (§22.6), and their per-RFC authority (§6.3/§12) —
+# with the §22.5 visibility gate and the §6.2 write-mute *subtractive* on top
+# (§22.7). The per-RFC capability helpers below (`can_discuss_rfc`,
+# `can_contribute_to_rfc`, `can_invite_to_rfc`) compose all three tiers, so the
+# ~20 endpoint call sites inherit multi-project behavior unchanged.
+#
+# Through Slice M2 the only project is the migration-seeded `default` one (the
+# N=1 case, §22.13); a project is resolved from an RFC slug via
+# `cached_rfcs.project_id` (unique per slug while N=1). M3's registry mirror
+# lets a deployment declare a second project; these gates already hold then.
+#
+# OPERATOR DECISIONS (M2):
+#  * implicit-on-public — on a `public` project a granted deployment
+#    `contributor` keeps the pre-multi-project write *baseline* (propose
+#    freely; an owned RFC's discuss/contribute is still gated by the v0.16.0
+#    per-RFC invite). No project_members row is needed and no backfill runs,
+#    so the N=1 case stays whole. Explicit project_members rows and
+#    gated/unlisted visibility are where the new tier actually bites.
+#  * preserve curation — the implicit-public baseline does NOT override per-RFC
+#    owner curation; only an *explicit* project_contributor/project_admin grant
+#    (or a deployment owner/admin) bypasses it. So §22.7's "project_contributor
+#    ⊇ rfc_collaborators(contributor)" holds for explicit grants, while a plain
+#    granted contributor on public behaves exactly as it did before M2.
+# ===========================================================================
+
+_DEPLOYMENT_SUPERUSER_ROLES = ("owner", "admin")
+
+
+def project_visibility(project_id: str) -> str:
+    """The project's §22.5 visibility ('gated' | 'public' | 'unlisted'). A
+    missing row reads as 'gated' — the safe default: an unknown project is
+    invisible rather than open."""
+    row = db.conn().execute(
+        "SELECT visibility FROM projects WHERE id = ?", (project_id,)
+    ).fetchone()
+    if row is None:
+        return "gated"
+    return row["visibility"] or "gated"
+
+
+def _is_default_project(project_id: str) -> bool:
+    """True iff `project_id` owns the migration-seeded `default` collection — the
+    deployment's primary project (§22.13), whatever its configured id. Only there
+    do M2's role rows (which migrated to collection scope `default`) stand in for
+    project-level authority."""
+    return collections_mod.project_of_collection(collections_mod.DEFAULT_COLLECTION_ID) == project_id
+
+
+def project_member_role(user: SessionUser | None, project_id: str) -> str | None:
+    """The user's *project-grain* §22.6 role at this project, or None — the
+    most-permissive of a **global** grant (inherits down to every project) and a
+    **project**-scope grant. Mapped back to the legacy
+    `project_admin`/`project_contributor` strings the project-grain authz speaks.
+
+    Back-compat: on the deployment's *default* project only, M2's rows live at
+    collection scope `default` (§B.3 migration), so a `default` collection-scope
+    grant there is read as project-level too. A collection grant on any other
+    project is NOT project authority — that is the four-layer collection resolver
+    (`effective_scope_role`). Does not fold in the deployment tier
+    (`is_project_superuser` adds it) or the implicit-on-public baseline."""
+    if user is None:
+        return None
+    clauses = ["scope_type = 'global'", "(scope_type = 'project' AND scope_id = ?)"]
+    params: list = [user.user_id, project_id]
+    if _is_default_project(project_id):
+        clauses.append("(scope_type = 'collection' AND scope_id = ?)")
+        params.append(collections_mod.DEFAULT_COLLECTION_ID)
+    row = db.conn().execute(
+        "SELECT role FROM memberships WHERE user_id = ? AND (" + " OR ".join(clauses) + ") "
+        "ORDER BY CASE role WHEN 'owner' THEN 0 ELSE 1 END LIMIT 1",
+        params,
+    ).fetchone()
+    if row is None:
+        return None
+    return "project_admin" if row["role"] == "owner" else "project_contributor"
+
+
+def project_of_rfc(rfc_slug: str) -> str:
+    """The project an RFC belongs to, via its collection
+    (`cached_rfcs.collection_id` -> `collections.project_id`, §22 three-tier).
+    Falls back to the default project when the slug isn't cached — the same N=1
+    default migration 026 backfills."""
+    row = db.conn().execute(
+        "SELECT c.project_id AS project_id "
+        "FROM cached_rfcs r JOIN collections c ON c.id = r.collection_id "
+        "WHERE r.slug = ?",
+        (rfc_slug,),
+    ).fetchone()
+    if row is None:
+        return DEFAULT_PROJECT_ID
+    return row["project_id"] or DEFAULT_PROJECT_ID
+
+
+def collection_of_rfc(rfc_slug: str) -> str:
+    """The collection an RFC belongs to (`cached_rfcs.collection_id`). Falls back
+    to the default collection when the slug isn't cached. Mirrors
+    `project_of_rfc`'s first-match semantics; a slug shared across collections is
+    a known routing ambiguity (the RFC-grain helpers take a bare slug) resolved
+    by the collection-qualified routes in later slices."""
+    row = db.conn().execute(
+        "SELECT collection_id FROM cached_rfcs WHERE slug = ?", (rfc_slug,)
+    ).fetchone()
+    if row is None or not row["collection_id"]:
+        return collections_mod.DEFAULT_COLLECTION_ID
+    return row["collection_id"]
+
+
+def is_project_superuser(user: SessionUser | None, project_id: str) -> bool:
+    """Maximal authority within a project: a deployment owner/admin (superuser
+    in every project, §22.7) or an explicit `project_admin` (§22.6). Both
+    subsume the per-RFC owners/arbiters tier."""
+    if user is None:
+        return False
+    if user.role in _DEPLOYMENT_SUPERUSER_ROLES:
+        return True
+    return project_member_role(user, project_id) == "project_admin"
+
+
+def can_read_project(user: SessionUser | None, project_id: str) -> bool:
+    """The §22.5 visibility gate at the project grain. `public`/`unlisted` are
+    readable by anyone (anonymous included — `unlisted` is link-only but the link
+    still reads); `gated` is readable only by a deployment owner/admin or a
+    holder of any scope grant reaching the project — a global grant, a project
+    grant, or membership at *any* collection within it (seeing a collection
+    implies seeing its project). Used as the subtractive read gate (a gated
+    project's entries 404 to non-members)."""
+    vis = project_visibility(project_id)
+    if vis in ("public", "unlisted"):
+        return True
+    # gated — scope-role holders + superusers only, subject to the §6 floor.
+    if user is None or user.permission_state != "granted":
+        return False
+    if user.role in _DEPLOYMENT_SUPERUSER_ROLES:
+        return True
+    row = db.conn().execute(
+        "SELECT 1 FROM memberships m WHERE m.user_id = ? AND ("
+        "      m.scope_type = 'global'"
+        "   OR (m.scope_type = 'project' AND m.scope_id = ?)"
+        "   OR (m.scope_type = 'collection' AND m.scope_id IN "
+        "        (SELECT id FROM collections WHERE project_id = ?))) LIMIT 1",
+        (user.user_id, project_id, project_id),
+    ).fetchone()
+    return row is not None
+
+
+def require_project_readable(user: SessionUser | None, project_id: str) -> None:
+    """Raise 404 when the project is not readable by this viewer (§22.5: a
+    gated project is invisible to non-members — indistinguishable from absent,
+    so the shape matches an unknown slug)."""
+    if not can_read_project(user, project_id):
+        raise HTTPException(status_code=404, detail="RFC not found")
+
+
+def _has_write_baseline(user: SessionUser | None, project_id: str) -> bool:
+    """The implicit-on-public write baseline: a granted deployment
+    `contributor` on a `public` project carries the pre-multi-project
+    write standing (still subject to per-RFC curation). Deployment
+    owner/admin are handled by `is_project_superuser`; on gated/unlisted a
+    contributor has no baseline and needs an explicit project role."""
+    if user is None or user.permission_state != "granted":
+        return False
+    return user.role == "contributor" and project_visibility(project_id) == "public"
+
+
+def can_contribute_in_project(user: SessionUser | None, project_id: str) -> bool:
+    """May the user contribute *new* content to the project (propose an entry)
+    — the project-level (not RFC-specific) contribute standing. The union of
+    the override grants (superuser / explicit project_contributor) and the
+    implicit-public baseline, subject to the visibility gate."""
+    if user is None or user.permission_state != "granted":
+        return False
+    if not can_read_project(user, project_id):
+        return False
+    if is_project_superuser(user, project_id):
+        return True
+    if project_member_role(user, project_id) == "project_contributor":
+        return True
+    return _has_write_baseline(user, project_id)
+
+
+def can_discuss_in_project(user: SessionUser | None, project_id: str) -> bool:
+    """May the user participate in discussion in the project at all — the
+    project-level discuss standing (project_viewer ⊇ discussant, §22.7).
+    A superset of `can_contribute_in_project` (a contributor can discuss)."""
+    if user is None or user.permission_state != "granted":
+        return False
+    if not can_read_project(user, project_id):
+        return False
+    if is_project_superuser(user, project_id):
+        return True
+    if project_member_role(user, project_id) in ("project_viewer", "project_contributor"):
+        return True
+    return _has_write_baseline(user, project_id)
+
+
+def visible_project_ids(user: SessionUser | None) -> list[str]:
+    """Project ids whose entries may surface in a listing for this viewer — the
+    §22.5 read gate applied to the catalog/idea lists. (The directory's
+    `unlisted`-omission and the per-project routing are M3 concerns; for the M2
+    listing filter we include every project the viewer can read.)"""
+    rows = db.conn().execute("SELECT id FROM projects").fetchall()
+    return [r["id"] for r in rows if can_read_project(user, r["id"])]
+
+
+# ===========================================================================
+# §22 three-tier — S3. The four-layer scope-role resolver (§B.2) and the
+# collection-grain visibility gate.
+#
+# A grant attaches the unified role {owner, contributor} at a scope: global,
+# project, or collection (§B.1). Grants inherit downward, are additive, and
+# admit no negative override (§B.2). Effective authority over a *collection* is
+# the most-permissive union of the layers reaching it:
+#
+#     global   (users.role owner/admin  ∪  memberships scope_type='global')
+#   ∪ project  (memberships scope_type='project'    at the collection's project)
+#   ∪ collection (memberships scope_type='collection' at the collection)
+#
+# minus the §22.5 visibility gate and §6.2 write-mute (subtractive, as today).
+# Per-entry authority (owners / arbiters / rfc_collaborators) is a distinct,
+# finer layer the RFC-grain helpers union in beneath collection.
+#
+# OPERATOR DECISIONS (S3, session 0076):
+#  * scope-role-primary — a plain granted account (users.role 'contributor', no
+#    membership) is a granted *account*, not a write-everywhere global role.
+#    Write standing comes from an explicit scope grant; the lone exception is the
+#    grandfathered implicit-public baseline below.
+#  * grandfathered baseline — the migration-seeded `default` collection keeps the
+#    pre-three-tier implicit-on-public write baseline (a granted deployment
+#    contributor may propose while it is public), so the N=1 deployment (§22.13)
+#    loses no capability. Every *explicitly-created* collection requires an
+#    explicit scope grant to write.
+#  * hidden-from-public — a `gated` collection is invisible to the public (404,
+#    omitted from the directory) yet visible to any scope-role holder reaching it
+#    (collection/project/global). A collection's visibility may be set only as
+#    strict or stricter than its project's (the rank ordering below).
+# ===========================================================================
+
+# The global scope is a single tier per deployment; its grant rows use this
+# sentinel scope_id (migration 030).
+GLOBAL_SCOPE_ID = "*"
+
+# §22.5 visibility strictness on the public-exposure axis: `public` is least
+# strict, `gated` most strict. A collection may narrow its project's visibility
+# but never widen it (`rank(collection) >= rank(project)`).
+_VISIBILITY_RANK = {"public": 0, "unlisted": 1, "gated": 2}
+
+
+def visibility_rank(visibility: str | None) -> int:
+    """The strictness rank of a §22.5 visibility (higher = stricter). An unknown
+    value reads as the strictest (`gated`) — the safe default."""
+    return _VISIBILITY_RANK.get(visibility or "", _VISIBILITY_RANK["gated"])
+
+
+def effective_scope_role(user: SessionUser | None, collection_id: str) -> str | None:
+    """The most-permissive unified role ({'owner','contributor'}) the user holds
+    over `collection_id`, folding §B.2's global → project → collection layers.
+    Returns None when no scope grant reaches the collection. 'owner' outranks
+    'contributor'; there is no negative override (a parent grant is never
+    subtracted by a child). Subject to the §6 admission floor."""
+    if user is None or user.permission_state != "granted":
+        return None
+    # Global tier — a deployment owner/admin is a global Owner (§B.1).
+    if user.role in _DEPLOYMENT_SUPERUSER_ROLES:
+        return "owner"
+    pid = collections_mod.project_of_collection(collection_id)
+    row = db.conn().execute(
+        "SELECT role FROM memberships "
+        "WHERE user_id = ? AND ("
+        "      scope_type = 'global'"
+        "   OR (scope_type = 'project' AND scope_id = ?)"
+        "   OR (scope_type = 'collection' AND scope_id = ?)) "
+        "ORDER BY CASE role WHEN 'owner' THEN 0 ELSE 1 END LIMIT 1",
+        (user.user_id, pid, collection_id),
+    ).fetchone()
+    return row["role"] if row else None
+
+
+def _effective_project_role(user: SessionUser | None, project_id: str) -> str | None:
+    """The most-permissive role the user holds *over a project* — folding the
+    global tier (deployment owner/admin, or a `scope_type='global'` grant) and a
+    `scope_type='project'` grant on this project. Unlike `effective_scope_role`
+    (which keys on a collection), this answers the project grain directly, for the
+    §22.8 request-to-join membership check. Subject to the §6 admission floor."""
+    if user is None or user.permission_state != "granted":
+        return None
+    if user.role in _DEPLOYMENT_SUPERUSER_ROLES:
+        return "owner"
+    row = db.conn().execute(
+        "SELECT role FROM memberships "
+        "WHERE user_id = ? AND ("
+        "      scope_type = 'global'"
+        "   OR (scope_type = 'project' AND scope_id = ?)) "
+        "ORDER BY CASE role WHEN 'owner' THEN 0 ELSE 1 END LIMIT 1",
+        (user.user_id, project_id),
+    ).fetchone()
+    return row["role"] if row else None
+
+
+def effective_role_at_scope(
+    user: SessionUser | None, scope_type: str, scope_id: str
+) -> str | None:
+    """The most-permissive scope role the user holds over a `(scope_type,
+    scope_id)` target — the scope-grain twin of `effective_scope_role`. A
+    `collection` target folds global → project → collection (the existing
+    resolver); a `project` target folds global → project. Returns None when no
+    grant reaches the scope. Drives the §22.8 "already a member?" gate."""
+    if scope_type == "collection":
+        return effective_scope_role(user, scope_id)
+    if scope_type == "project":
+        return _effective_project_role(user, scope_id)
+    return None
+
+
+def collection_visibility(collection_id: str) -> str:
+    """The collection's own §22.5 visibility. A missing row reads as 'gated' —
+    an unknown collection is invisible rather than open."""
+    row = db.conn().execute(
+        "SELECT visibility FROM collections WHERE id = ?", (collection_id,)
+    ).fetchone()
+    if row is None or not row["visibility"]:
+        return "gated"
+    return row["visibility"]
+
+
+def effective_collection_visibility(collection_id: str) -> str:
+    """The stricter of the collection's own visibility and its project's (§22.5
+    'both gates'). A collection is constrained to be ≥ its project in strictness,
+    but we max() defensively so a misconfigured looser collection can never widen
+    its project's gate."""
+    cvis = collection_visibility(collection_id)
+    pid = collections_mod.project_of_collection(collection_id)
+    pvis = project_visibility(pid) if pid else "gated"
+    return cvis if visibility_rank(cvis) >= visibility_rank(pvis) else pvis
+
+
+def can_read_collection(user: SessionUser | None, collection_id: str) -> bool:
+    """§22.5 read/existence gate at the collection grain. `public`/`unlisted`
+    read by anyone (anonymous included — `unlisted` is link-only but the link
+    reads); `gated` ("hidden from public existence") reads only for a scope-role
+    holder over the collection (collection/project/global) or a deployment
+    owner/admin. The subtractive read gate — a gated collection 404s a
+    non-holder, indistinguishable from absent."""
+    vis = effective_collection_visibility(collection_id)
+    if vis in ("public", "unlisted"):
+        return True
+    if user is None or user.permission_state != "granted":
+        return False
+    return effective_scope_role(user, collection_id) is not None
+
+
+def require_collection_readable(user: SessionUser | None, collection_id: str) -> None:
+    """Raise 404 when the collection is not readable by this viewer (§22.5: a
+    hidden/gated collection is invisible to non-holders — the shape matches an
+    unknown collection)."""
+    if not can_read_collection(user, collection_id):
+        raise HTTPException(status_code=404, detail="Not found")
+
+
+def is_collection_superuser(user: SessionUser | None, collection_id: str) -> bool:
+    """Maximal authority over a collection: an effective scope role of 'owner'
+    reaching it (a collection Owner, a project Owner of its project, a global
+    Owner, or a deployment owner/admin). Subsumes the per-entry owners/arbiters
+    tier within the collection."""
+    return effective_scope_role(user, collection_id) == "owner"
+
+
+def _has_collection_write_baseline(user: SessionUser | None, collection_id: str) -> bool:
+    """The grandfathered implicit-on-public write baseline, narrowed to the
+    migration-seeded `default` collection (§22.13 N=1 case). A granted deployment
+    `contributor` keeps its pre-three-tier write standing on the default
+    collection while its effective visibility is public; every explicitly-created
+    collection requires an explicit scope grant (S3 operator decision)."""
+    if user is None or user.permission_state != "granted":
+        return False
+    if collection_id != collections_mod.DEFAULT_COLLECTION_ID:
+        return False
+    return user.role == "contributor" and effective_collection_visibility(collection_id) == "public"
+
+
+def can_contribute_in_collection(user: SessionUser | None, collection_id: str) -> bool:
+    """May the user contribute *new* content to the collection (propose an entry)
+    — the collection-level contribute standing. The union of the scope-role grant
+    (owner/contributor reaching the collection) and the grandfathered default
+    baseline, subject to the visibility read gate."""
+    if user is None or user.permission_state != "granted":
+        return False
+    if not can_read_collection(user, collection_id):
+        return False
+    if effective_scope_role(user, collection_id) is not None:
+        return True
+    return _has_collection_write_baseline(user, collection_id)
+
+
+def can_discuss_in_collection(user: SessionUser | None, collection_id: str) -> bool:
+    """May the user participate in discussion in the collection — the
+    collection-level discuss standing. A superset of contribute for this pass
+    (the read-only viewer tier is deferred, §B.3), so it mirrors
+    `can_contribute_in_collection`."""
+    return can_contribute_in_collection(user, collection_id)
+
+
+def can_create_collection(user: SessionUser | None, project_id: str) -> bool:
+    """May the user create a new collection in this project (§B.1)? Creating a
+    collection is a *project-level* action: a deployment owner/admin, or any
+    holder of a project-scope or global-scope grant (Owner OR RFC Contributor —
+    'anyone at the project level with permission to create a collection'). A
+    *collection*-scope grant cannot create sibling collections."""
+    if user is None or user.permission_state != "granted":
+        return False
+    if user.role in _DEPLOYMENT_SUPERUSER_ROLES:
+        return True
+    row = db.conn().execute(
+        "SELECT 1 FROM memberships "
+        "WHERE user_id = ? AND ("
+        "      scope_type = 'global'"
+        "   OR (scope_type = 'project' AND scope_id = ?)) LIMIT 1",
+        (user.user_id, project_id),
+    ).fetchone()
+    return row is not None
+
+
+def can_create_project(user: SessionUser | None) -> bool:
+    """§22 S5 (§A.2 / §B.1): may the user create a new project? "+ New project"
+    is a **global-Owner** action — a deployment owner/admin (a global Owner per
+    §B.1) or a holder of an explicit `scope_type='global'` Owner grant. Creating
+    a project is deployment-level, so it is not reachable by a project- or
+    collection-scope grant nor by a global RFC Contributor (that role creates
+    collections, not projects). Subject to the §6 admission floor."""
+    if user is None or user.permission_state != "granted":
+        return False
+    if user.role in _DEPLOYMENT_SUPERUSER_ROLES:
+        return True
+    row = db.conn().execute(
+        "SELECT 1 FROM memberships "
+        "WHERE user_id = ? AND scope_type = 'global' AND role = 'owner' LIMIT 1",
+        (user.user_id,),
+    ).fetchone()
+    return row is not None
+
+
+def can_invite_at_project(user: SessionUser | None, project_id: str) -> bool:
+    """§22 S4 (C.2): may the user grant scope roles at this project (or at any
+    collection within it)? Managing membership is an *Owner* capability whose
+    reach covers the project — a deployment owner/admin, a global Owner, or this
+    project's Owner. An RFC Contributor does not manage membership (C.2.4); a
+    collection Owner's reach is its own collection only (C.2.3), so it is not
+    offered project-scope invites. Identical to `is_project_superuser` — the
+    invite gate IS "is an Owner over this project"."""
+    return is_project_superuser(user, project_id)
+
+
+def can_invite_at_collection(user: SessionUser | None, collection_id: str) -> bool:
+    """§22 S4 (C.2): may the user grant scope roles at this collection? An Owner
+    whose reach covers it — the collection's Owner, its project's Owner, a global
+    Owner, or a deployment owner/admin (`is_collection_superuser`). This is the
+    narrowest invite reach; a collection Owner who is nothing more may invite
+    here but not at the project or globally (C.2.3)."""
+    return is_collection_superuser(user, collection_id)
+
+
 # v0.16.0 (roadmap item #12): per-RFC membership helpers.
 #
 # These don't replace `require_contributor` — they layer on top of it for
@@ -386,18 +853,28 @@ def can_discuss_rfc(user: SessionUser | None, rfc_slug: str) -> bool:
         return False
     if user.permission_state != "granted":
         return False
-    if user.role in ("owner", "admin"):
+    cid = collection_of_rfc(rfc_slug)
+    # §22.5 visibility gate is subtractive (§22.7) — no capability in a
+    # collection the viewer cannot even read.
+    if not can_read_collection(user, cid):
+        return False
+    # §B.2 union, scope-role grants first — these bypass per-RFC curation (a
+    # collection/project/global Owner or RFC Contributor ⊇ discussant).
+    if effective_scope_role(user, cid) is not None:
         return True
+    # per-RFC authority (union term).
     owners = _rfc_owners_set(rfc_slug)
-    if not owners:
-        # No owner to gate the invite-list — fall through to the
-        # platform-granted contract. The first §13.1 claim engages
-        # the gate; before that, anyone platform-granted can
-        # contribute (mirrors the v0.5.0 / v0.6.0 contract).
-        return True
     if user.gitea_login in owners:
         return True
-    return is_rfc_collaborator(user, rfc_slug, role_in_rfc=None)
+    if is_rfc_collaborator(user, rfc_slug, role_in_rfc=None):
+        return True
+    # grandfathered implicit-public baseline (curation preserved): on the default
+    # collection a granted deployment contributor may discuss only while the RFC
+    # is unclaimed. The first §13.1 claim engages the per-RFC gate, mirroring the
+    # pre-multi-project v0.16.0 contract.
+    if not owners and _has_collection_write_baseline(user, cid):
+        return True
+    return False
 
 
 def can_contribute_to_rfc(user: SessionUser | None, rfc_slug: str) -> bool:
@@ -419,16 +896,26 @@ def can_contribute_to_rfc(user: SessionUser | None, rfc_slug: str) -> bool:
         return False
     if user.permission_state != "granted":
         return False
-    if user.role in ("owner", "admin"):
+    cid = collection_of_rfc(rfc_slug)
+    if not can_read_collection(user, cid):
+        return False
+    # §B.2 union, scope-role grants first (a collection/project/global RFC
+    # Contributor ⊇ rfc_collaborators(contributor); an Owner ⊇ all).
+    if effective_scope_role(user, cid) is not None:
         return True
+    # per-RFC authority (union term). A 'discussant' row is NOT sufficient —
+    # PRs are the higher-privilege surface.
     owners = _rfc_owners_set(rfc_slug)
-    if not owners:
-        # Same fall-through as can_discuss_rfc: until an owner exists,
-        # the gate is open.
-        return True
     if user.gitea_login in owners:
         return True
-    return is_rfc_collaborator(user, rfc_slug, role_in_rfc="contributor")
+    if is_rfc_collaborator(user, rfc_slug, role_in_rfc="contributor"):
+        return True
+    # grandfathered implicit-public baseline (curation preserved): until an owner
+    # exists, a granted deployment contributor on the public default collection
+    # may contribute.
+    if not owners and _has_collection_write_baseline(user, cid):
+        return True
+    return False
 
 
 def can_invite_to_rfc(user: SessionUser | None, rfc_slug: str) -> bool:
@@ -439,7 +926,13 @@ def can_invite_to_rfc(user: SessionUser | None, rfc_slug: str) -> bool:
         return False
     if user.permission_state != "granted":
         return False
-    if user.role in ("owner", "admin"):
+    cid = collection_of_rfc(rfc_slug)
+    if not can_read_collection(user, cid):
+        return False
+    # An Owner reaching the collection (collection/project/global Owner, or a
+    # deployment owner/admin) may invite; otherwise only the RFC's frontmatter
+    # owner. Per-RFC collaborators and the baseline do not get the invite power.
+    if is_collection_superuser(user, cid):
         return True
     return is_rfc_owner(user, rfc_slug)
 

backend/app/bot.py

@@ -27,7 +27,7 @@ import json
 import logging
 from dataclasses import dataclass
 
-from . import db, notify
+from . import db, entry as entry_mod, notify
 from .gitea import Gitea, GiteaError
 
 log = logging.getLogger(__name__)
@@ -163,6 +163,117 @@ class Bot:
     def __init__(self, gitea: Gitea):
         self._gitea = gitea
 
+    # ----- Content repo: collection structure (§22 S2) -----
+
+    async def create_collection(
+        self,
+        actor: Actor,
+        *,
+        org: str,
+        content_repo: str,
+        collection_id: str,
+        manifest_yaml: str,
+    ) -> dict:
+        """§22 S2: commit `<collection_id>/.collection.yaml` to the content
+        repo's main. A structural admin action — committed straight to main (no
+        PR), like the registry config it feeds; the registry mirror then upserts
+        the collections row (§22.2 keeps the registry the source of truth). Logs
+        an audit row for the §6.5 trail."""
+        path = f"{collection_id}/.collection.yaml"
+        created = await self._gitea.create_file(
+            org,
+            content_repo,
+            path,
+            content=manifest_yaml,
+            message=_stamp_single(f"chore: create collection {collection_id}", actor),
+            branch="main",
+            author_name=actor.display_name,
+            author_email=actor.email or f"{actor.gitea_login}@users.noreply",
+        )
+        _log(
+            actor,
+            "create_collection",
+            bot_commit_sha=created.get("commit", {}).get("sha"),
+            details={"collection_id": collection_id, "repo": content_repo},
+        )
+        return created
+
+    async def create_project(
+        self,
+        actor: Actor,
+        *,
+        org: str,
+        registry_repo: str,
+        content_repo: str,
+        project_id: str,
+        projects_yaml_new: str,
+        projects_yaml_sha: str,
+        readme_text: str,
+    ) -> dict:
+        """§22 S5 (§A.2): stand up a new project. A global-Owner action wrapping
+        a bot write at two git sources:
+
+          1. **provision the content repo** — create `org/content_repo` if it
+             doesn't exist, then seed a `README.md` on `main` so the branch
+             exists (the contents API initialises the repo with that commit; the
+             corpus mirror and the propose path both need a `main` to write to).
+          2. **register the project** — commit the caller-composed
+             `projects.yaml` (the existing doc with the new project appended) to
+             the registry repo's `main`.
+
+        Like `create_collection`, this is a structural admin action committed
+        straight to main (no PR), like the registry config it feeds; the caller
+        then re-runs the registry mirror so the new `projects` + default
+        `collections` rows flow from the registry (§22.2 keeps the registry the
+        source of truth). Logs a `create_project` audit row for the §6.5 trail.
+        Returns the registry update_file result (carries the new commit sha)."""
+        ae = actor.email or f"{actor.gitea_login}@users.noreply"
+        existing = await self._gitea.get_repo(org, content_repo)
+        if existing is None:
+            await self._gitea.create_org_repo(
+                org, content_repo, description=f"Content repo for project {project_id}"
+            )
+        # Seed a README if absent, which also establishes `main` on a freshly
+        # created (auto_init=False) repo — the contents API initialises the repo
+        # with that commit. Keyed on the README rather than the branch so it is
+        # idempotent and behaves identically whether the repo has a bare `main`
+        # or no branch at all. Mirrors `ensure_rfc_repo_seed`'s empty-repo seed.
+        readme = await self._gitea.get_contents(org, content_repo, "README.md", ref="main")
+        if readme is None:
+            await self._gitea.create_file(
+                org,
+                content_repo,
+                "README.md",
+                content=readme_text,
+                message=_stamp_single(f"chore: initialise content repo for {project_id}", actor),
+                branch="main",
+                author_name=actor.display_name,
+                author_email=ae,
+            )
+        result = await self._gitea.update_file(
+            org,
+            registry_repo,
+            "projects.yaml",
+            content=projects_yaml_new,
+            sha=projects_yaml_sha,
+            message=_stamp_single(f"chore: create project {project_id}", actor),
+            branch="main",
+            author_name=actor.display_name,
+            author_email=ae,
+        )
+        commit_sha = (
+            result.get("commit", {}).get("sha")
+            or result.get("content", {}).get("sha")
+            or ""
+        )
+        _log(
+            actor,
+            "create_project",
+            bot_commit_sha=commit_sha,
+            details={"project_id": project_id, "content_repo": content_repo},
+        )
+        return result
+
     # ----- Meta repo: idea PRs (§9.1 / §9.2) -----
 
     async def open_idea_pr(
@@ -175,12 +286,16 @@ class Bot:
         file_contents: str,
         pr_title: str,
         pr_description: str,
+        rfcs_dir: str = "rfcs",
     ) -> dict:
-        """Per §9.1: open a meta-repo PR adding one file under rfcs/.
+        """Per §9.1: open a meta-repo PR adding one file under `<rfcs_dir>/`.
 
         One file per PR keeps idea submissions atomic and conflict-free.
         The PR title and the file-add commit subject share §9.2's fixed
-        pattern; callers compose `pr_title` as `Propose: <Title>`.
+        pattern; callers compose `pr_title` as `Propose: <Title>`. §22 S2:
+        `rfcs_dir` carries the target collection's `<subfolder>/rfcs` so a
+        propose into a named collection writes under its subfolder; it
+        defaults to `rfcs` (the default collection / shipped behaviour).
         """
         branch = f"propose/{slug}"
         await self._gitea.create_branch(org, meta_repo, branch, from_branch="main")
@@ -189,7 +304,7 @@ class Bot:
         created = await self._gitea.create_file(
             org,
             meta_repo,
-            f"rfcs/{slug}.md",
+            f"{rfcs_dir}/{slug}.md",
             content=file_contents,
             message=commit_message,
             branch=branch,
@@ -695,111 +810,7 @@ class Bot:
         )
         return sha
 
-    # ----- §13 graduation: per-step primitives and rollback inverses -----
-
-    async def create_rfc_repo_for_graduation(
-        self,
-        actor: Actor,
-        *,
-        org: str,
-        repo_name: str,
-        slug: str,
-        title: str,
-    ) -> dict:
-        """§13.3 step 1: create the per-RFC repo.
-
-        Empty repo (no auto-init) — `seed_graduated_rfc` writes the first
-        commit on `main`. Returns the Gitea repo payload."""
-        repo = await self._gitea.create_org_repo(
-            org, repo_name, description=f"RFC: {title}"
-        )
-        _log(
-            actor,
-            "graduate_repo_create",
-            rfc_slug=slug,
-            details={"repo": f"{org}/{repo_name}", "title": title},
-        )
-        return repo
-
-    async def seed_graduated_rfc(
-        self,
-        actor: Actor,
-        *,
-        org: str,
-        repo_name: str,
-        slug: str,
-        title: str,
-        rfc_body: str,
-        rfc_id: str,
-        meta_full: str,
-        meta_path: str,
-        owners: list[str],
-        arbiters: list[str],
-        tags: list[str],
-    ) -> str:
-        """§13.3 step 2: seed RFC.md, README.md, .rfc/metadata.yaml on the
-        new repo's `main`. Three create_file calls; one audit row.
-
-        Returns the final commit sha on main.
-        """
-        import yaml as _yaml
-
-        ae = actor.email or f"{actor.gitea_login}@users.noreply"
-        # 2a) RFC.md — the document. The super-draft's body is migrated
-        # verbatim per §13.3; if the body is empty we seed a minimal
-        # placeholder so the editor has something to render on first open.
-        body = rfc_body.strip() + "\n" if rfc_body.strip() else (
-            f"# {title}\n\n*RFC.md to be filled in — the super-draft graduated with an empty body.*\n"
-        )
-        rfc_msg = _stamp_single(f"Seed RFC.md from super-draft {slug}", actor)
-        rfc_result = await self._gitea.create_file(
-            org, repo_name, "RFC.md",
-            content=body, message=rfc_msg, branch="main",
-            author_name=actor.display_name, author_email=ae,
-        )
-        # 2b) README.md — header pointing back at the meta-repo entry.
-        readme = (
-            f"# {rfc_id} — {title}\n\n"
-            f"This repository carries the canonical text of {rfc_id}.\n"
-            f"The meta-repo entry is `{meta_path}` in `{meta_full}`.\n\n"
-            f"The RFC body is in `RFC.md`. Contributions go through the\n"
-            f"app's §8 RFC view — open a branch, propose changes, land a PR.\n"
-        )
-        readme_msg = _stamp_single(f"Seed README.md for {rfc_id}", actor)
-        await self._gitea.create_file(
-            org, repo_name, "README.md",
-            content=readme, message=readme_msg, branch="main",
-            author_name=actor.display_name, author_email=ae,
-        )
-        # 2c) .rfc/metadata.yaml — mirror of meta-repo frontmatter for
-        # future tooling (linting, automation, CI lookups).
-        meta_yaml = _yaml.safe_dump(
-            {
-                "slug": slug, "title": title, "id": rfc_id,
-                "owners": owners, "arbiters": arbiters, "tags": list(tags),
-            },
-            sort_keys=False,
-        )
-        meta_msg = _stamp_single(f"Seed .rfc/metadata.yaml for {rfc_id}", actor)
-        meta_result = await self._gitea.create_file(
-            org, repo_name, ".rfc/metadata.yaml",
-            content=meta_yaml, message=meta_msg, branch="main",
-            author_name=actor.display_name, author_email=ae,
-        )
-        last_sha = (
-            meta_result.get("commit", {}).get("sha")
-            or rfc_result.get("commit", {}).get("sha")
-            or ""
-        )
-        _log(
-            actor,
-            "graduate_repo_seed",
-            rfc_slug=slug,
-            branch_name="main",
-            bot_commit_sha=last_sha,
-            details={"repo": f"{org}/{repo_name}", "rfc_id": rfc_id},
-        )
-        return last_sha
+    # ----- §13 graduation (meta-only): open + merge the flip PR -----
 
     async def open_graduation_pr(
         self,
@@ -810,12 +821,15 @@ class Bot:
         slug: str,
         new_file_contents: str,
         prior_sha: str,
-        rfc_id: str,
-        repo_full: str,
+        rfc_id: str | None,
         owners: list[str],
     ) -> dict:
-        """§13.3 step 3: open a PR against the meta repo that strips the
-        super-draft body and fills graduation frontmatter fields. Branch
+        """§13.3 (meta-only): open a PR against the meta repo that flips the
+        entry's frontmatter to `state: active` with the graduation stamps
+        and — **optionally** — the integer `id`, **keeping the body
+        unchanged** (§1 meta-only topology; no repo is created and no body
+        is stripped). When `rfc_id` is None the entry graduates without a
+        number (id stays null, slug is canonical per §2.3, §13.2). Branch
         name uses the `graduate-<slug>-<6hex>` shape — dash-separated like
         the other meta-repo branches per the §19.2 path-routing candidate.
         """
@@ -824,7 +838,7 @@ class Bot:
         branch = f"graduate-{slug}-{secrets.token_hex(3)}"
         await self._gitea.create_branch(org, meta_repo, branch, from_branch="main")
         ae = actor.email or f"{actor.gitea_login}@users.noreply"
-        commit_subject = f"Graduate {slug} → {rfc_id}"
+        commit_subject = f"Graduate {slug} → {rfc_id}" if rfc_id else f"Graduate {slug} (no number)"
         commit_message = _stamp_single(commit_subject, actor)
         result = await self._gitea.update_file(
             org, meta_repo, f"rfcs/{slug}.md",
@@ -839,16 +853,17 @@ class Bot:
             or result.get("content", {}).get("sha")
             or ""
         )
-        pr_title = f"Graduate {slug} → {rfc_id}"
+        pr_title = f"Graduate {slug} → {rfc_id}" if rfc_id else f"Graduate {slug} (no number)"
         owners_str = ", ".join(owners) if owners else "(none)"
+        id_line = f"- ID: `{rfc_id}`\n" if rfc_id else "- ID: (none — identified by slug)\n"
         pr_body_text = (
             f"Graduates super-draft `{slug}` to active.\n\n"
-            f"- ID: `{rfc_id}`\n"
-            f"- Repo: `{repo_full}`\n"
+            f"{id_line}"
             f"- Owners: {owners_str}\n\n"
-            f"The meta-repo entry becomes frontmatter-only; the canonical body\n"
-            f"moves to `RFC.md` in the new repo. The graduation sequence is\n"
-            f"transactional per §13.3."
+            f"This is an in-place state flip per the meta-only topology\n"
+            f"(SPEC §1, §13.3): the entry `rfcs/{slug}.md` keeps its body and\n"
+            f"stays in the meta repo. Only the frontmatter changes — `state`,\n"
+            f"`id`, and the graduation stamps."
         )
         _subject, pr_body = _stamp("", pr_body_text, actor)
         pr = await self._gitea.create_pull(
@@ -862,7 +877,7 @@ class Bot:
             branch_name=branch,
             pr_number=pr["number"],
             bot_commit_sha=commit_sha,
-            details={"pr_title": pr_title, "rfc_id": rfc_id, "repo": repo_full},
+            details={"pr_title": pr_title, "rfc_id": rfc_id},
         )
         return pr
 
@@ -875,7 +890,7 @@ class Bot:
         pr_number: int,
         head_branch: str,
         slug: str,
-        rfc_id: str,
+        rfc_id: str | None,
     ) -> None:
         """§13.3 step 4: auto-merge the graduation PR with the admin as
         merge actor. Distinct action_kind so the audit log carries the
@@ -891,7 +906,7 @@ class Bot:
         reports the transient state (belt-and-suspenders against the same
         race appearing in a different shape).
         """
-        subject = f"Graduate {slug} → {rfc_id}"
+        subject = f"Graduate {slug} → {rfc_id}" if rfc_id else f"Graduate {slug} (no number)"
         body = _trailer(actor)
 
         try:
@@ -912,27 +927,106 @@ class Bot:
             details={"rfc_id": rfc_id},
         )
 
-    # ----- §13.3 rollback inverses -----
+    # ----- §13.7 retire / un-retire: open + merge a state-flip PR -----
 
-    async def delete_rfc_repo(
+    async def open_retire_flip_pr(
         self,
         actor: Actor,
         *,
         org: str,
-        repo_name: str,
+        meta_repo: str,
         slug: str,
-        reason: str,
-    ) -> None:
-        """Undo of `create_rfc_repo_for_graduation`. Records `graduate_repo_delete`
-        in the audit log with the rollback reason so the §13.3 stack's
-        rendered failure surface can be reconstructed from `actions`."""
-        await self._gitea.delete_repo(org, repo_name)
+        new_file_contents: str,
+        prior_sha: str,
+        verb: str,
+        target_state: str,
+    ) -> dict:
+        """§13.7: open a PR flipping `rfcs/<slug>.md` to `state:
+        <target_state>` — for retire (`verb='retire'`, target `retired`)
+        or un-retire (`verb='unretire'`, target the restored prior state).
+        Only the frontmatter `state` changes; the body and every other
+        field (including the integer `id`) are kept, so an un-retire
+        restores the entry exactly. Branch shape mirrors graduation's
+        `<verb>-<slug>-<6hex>`.
+        """
+        import secrets
+
+        branch = f"{verb}-{slug}-{secrets.token_hex(3)}"
+        await self._gitea.create_branch(org, meta_repo, branch, from_branch="main")
+        ae = actor.email or f"{actor.gitea_login}@users.noreply"
+        verb_title = "Retire" if verb == "retire" else "Un-retire"
+        commit_subject = f"{verb_title} {slug}"
+        commit_message = _stamp_single(commit_subject, actor)
+        result = await self._gitea.update_file(
+            org, meta_repo, f"rfcs/{slug}.md",
+            content=new_file_contents,
+            sha=prior_sha,
+            message=commit_message,
+            branch=branch,
+            author_name=actor.display_name, author_email=ae,
+        )
+        commit_sha = (
+            result.get("commit", {}).get("sha")
+            or result.get("content", {}).get("sha")
+            or ""
+        )
+        pr_title = f"{verb_title} {slug}"
+        pr_body_text = (
+            f"{verb_title}s `{slug}` (state → `{target_state}`).\n\n"
+            f"This is an in-place frontmatter flip per SPEC §13.7 — the\n"
+            f"entry `rfcs/{slug}.md` keeps its body and every other field;\n"
+            f"only `state` changes."
+        )
+        _subject, pr_body = _stamp("", pr_body_text, actor)
+        pr = await self._gitea.create_pull(
+            org, meta_repo,
+            title=pr_title, body=pr_body, head=branch, base="main",
+        )
         _log(
             actor,
-            "graduate_repo_delete",
+            f"{verb}_pr_open",
             rfc_slug=slug,
-            details={"repo": f"{org}/{repo_name}", "reason": reason},
+            branch_name=branch,
+            pr_number=pr["number"],
+            bot_commit_sha=commit_sha,
+            details={"pr_title": pr_title, "target_state": target_state},
         )
+        return pr
+
+    async def merge_retire_flip_pr(
+        self,
+        actor: Actor,
+        *,
+        org: str,
+        meta_repo: str,
+        pr_number: int,
+        head_branch: str,
+        slug: str,
+        verb: str,
+    ) -> None:
+        """§13.7: auto-merge the retire / un-retire flip PR (same
+        mergeable-wait + retry shape as `merge_graduation_pr`)."""
+        verb_title = "Retire" if verb == "retire" else "Un-retire"
+        subject = f"{verb_title} {slug}"
+        body = _trailer(actor)
+        try:
+            await self._gitea.wait_for_mergeable(org, meta_repo, pr_number)
+        except TimeoutError as e:
+            raise GiteaError(409, str(e)) from e
+        await _merge_with_retry(
+            self._gitea, org, meta_repo, pr_number,
+            merge_message_title=subject, merge_message_body=body,
+        )
+        _log(
+            actor,
+            f"{verb}_pr_merge",
+            rfc_slug=slug,
+            branch_name=head_branch,
+            pr_number=pr_number,
+            details={},
+        )
+
+    # ----- §13.3 (meta-only): cleanup of an unmerged flip PR -----
 
     async def close_graduation_pr(
         self,
@@ -1090,6 +1184,54 @@ class Bot:
         )
         return pr
 
+    # ----- §22.4c: mark-reviewed (direct main write) -----
+
+    async def mark_entry_reviewed(
+        self,
+        actor: Actor,
+        *,
+        org: str,
+        meta_repo: str,
+        slug: str,
+        reviewed_by: str,
+        reviewed_at: str,
+    ) -> None:
+        """Clear §22.4c unreviewed on an active entry by rewriting its
+        frontmatter on main. Stamps the commit with the §6.5 On-behalf-of
+        trailer and writes an actions-log row, mirroring the graduation
+        stamp's bot-write shape."""
+        path = f"rfcs/{slug}.md"
+        result = await self._gitea.read_file(org, meta_repo, path, ref="main")
+        if result is None:
+            raise GiteaError(404, f"{path} not found")
+        text, sha = result
+        e = entry_mod.parse(text)
+        e.unreviewed = False
+        e.reviewed_at = reviewed_at
+        e.reviewed_by = reviewed_by
+        commit_message = _stamp_single(f"Mark {slug} reviewed", actor)
+        result = await self._gitea.update_file(
+            org, meta_repo, path,
+            content=entry_mod.serialize(e),
+            sha=sha,
+            message=commit_message,
+            branch="main",
+            author_name=actor.display_name,
+            author_email=actor.email or f"{actor.gitea_login}@users.noreply",
+        )
+        commit_sha = (
+            result.get("commit", {}).get("sha")
+            or result.get("content", {}).get("sha")
+            or ""
+        )
+        _log(
+            actor,
+            "mark_reviewed",
+            rfc_slug=slug,
+            bot_commit_sha=commit_sha,
+            details={"reviewed_by": reviewed_by, "reviewed_at": reviewed_at},
+        )
+
     # ----- Per-RFC repo: seeding (test/dev fixtures, future graduation) -----
 
     async def ensure_rfc_repo_seed(

backend/app/cache.py

@@ -27,7 +27,7 @@ import asyncio
 import json
 import logging
 
-from . import db, entry as entry_mod
+from . import db, entry as entry_mod, projects as projects_mod, registry as registry_mod
 from .config import Config
 from .gitea import Gitea, GiteaError
 
@@ -35,16 +35,46 @@ log = logging.getLogger(__name__)
 
 
 async def refresh_meta_repo(config: Config, gitea: Gitea) -> None:
-    """Re-read rfcs/ on the meta repo and reconcile cached_rfcs.
+    """Re-read rfcs/ on every project's content repo and reconcile cached_rfcs.
 
-    Idempotent. Safe to call on every meta-repo webhook and on every
-    reconciler sweep.
+    §22 (Plan B): a deployment has N projects (§22.1), each with its own
+    content_repo (§22.3). Mirror each into cached_rfcs stamped with that
+    project's id, so a second project's corpus renders under /p/<id>/. Idempotent;
+    safe on every content-repo webhook and reconciler sweep.
     """
-    org, repo = config.gitea_org, config.meta_repo
+    org = config.gitea_org
+    rows = db.conn().execute(
+        "SELECT id, content_repo FROM projects WHERE content_repo IS NOT NULL AND content_repo != ''"
+    ).fetchall()
+    if not rows:
+        log.warning("refresh_meta_repo: no projects with a content_repo yet; skipping")
+        return
+    for prow in rows:
+        await _refresh_project_corpus(org, prow["id"], prow["content_repo"], gitea)
+
+
+async def _refresh_project_corpus(org: str, project_id: str, repo: str, gitea: Gitea) -> None:
+    # §22 S2: the corpus grain is the collection. Mirror every collection of the
+    # project from its `<subfolder>/rfcs/` directory, keying cached_rfcs by the
+    # collection id. The default collection (subfolder '') reads `rfcs/` — the
+    # shipped path, unchanged. include_unlisted: the mirror serves every
+    # collection's content regardless of enumeration visibility.
+    from . import collections as collections_mod
+    for col in collections_mod.list_collections(project_id, include_unlisted=True):
+        await _refresh_collection_corpus(
+            org, project_id, repo, col["id"], col["subfolder"] or "", gitea
+        )
+
+
+async def _refresh_collection_corpus(
+    org: str, project_id: str, repo: str, collection_id: str, subfolder: str, gitea: Gitea
+) -> None:
+    rfcs_dir = f"{subfolder}/rfcs" if subfolder else "rfcs"
     try:
-        files = await gitea.list_dir(org, repo, "rfcs", ref="main")
+        files = await gitea.list_dir(org, repo, rfcs_dir, ref="main")
     except GiteaError as e:
-        log.warning("refresh_meta_repo: cannot list rfcs/: %s", e)
+        log.warning("refresh_meta_repo: %s/%s: cannot list %s: %s",
+                    project_id, collection_id, rfcs_dir, e)
         return
 
     seen_slugs: set[str] = set()
@@ -58,24 +88,31 @@ async def refresh_meta_repo(config: Config, gitea: Gitea) -> None:
         try:
             entry = entry_mod.parse(text)
         except Exception as parse_err:
-            log.warning("refresh_meta_repo: skipping %s: %s", f["path"], parse_err)
+            log.warning("refresh_meta_repo: %s/%s: skipping %s: %s",
+                        project_id, collection_id, f["path"], parse_err)
             continue
         if not entry.slug:
-            log.warning("refresh_meta_repo: skipping %s: missing slug", f["path"])
+            log.warning("refresh_meta_repo: %s/%s: skipping %s: missing slug",
+                        project_id, collection_id, f["path"])
             continue
         seen_slugs.add(entry.slug)
-        _upsert_cached_rfc(entry, body_sha=sha)
+        _upsert_cached_rfc(entry, body_sha=sha, collection_id=collection_id)
 
-    # Mark entries removed from the meta repo as withdrawn-without-trace.
-    # In practice the spec keeps withdrawn entries in rfcs/ as historical
-    # record (§3), so this branch fires only for entries deleted out of
-    # band. We leave the row but flag it for reconciler attention.
-    existing = {row["slug"] for row in db.conn().execute("SELECT slug FROM cached_rfcs")}
+    # Entries removed from a collection's rfcs/ — the spec keeps withdrawn entries
+    # as historical record (§3), so this fires only for out-of-band deletes;
+    # leave the row, scoped to this collection, for reconciler attention.
+    existing = {
+        row["slug"]
+        for row in db.conn().execute(
+            "SELECT slug FROM cached_rfcs WHERE collection_id = ?", (collection_id,)
+        )
+    }
     for missing in existing - seen_slugs:
-        log.info("refresh_meta_repo: %s no longer in rfcs/ — leaving cache row in place", missing)
+        log.info("refresh_meta_repo: %s/%s/%s no longer present — leaving cache row",
+                 project_id, collection_id, missing)
 
 
-def _upsert_cached_rfc(entry: entry_mod.Entry, body_sha: str) -> None:
+def _upsert_cached_rfc(entry: entry_mod.Entry, body_sha: str, collection_id: str = "default") -> None:
     # §6.6: models_json stays NULL when the frontmatter key is absent
     # (inherit operator universe) and '[]' for the explicit opt-out.
     models_json = json.dumps(entry.models) if entry.models is not None else None
@@ -87,9 +124,11 @@ def _upsert_cached_rfc(entry: entry_mod.Entry, body_sha: str) -> None:
         INSERT INTO cached_rfcs
             (slug, title, state, rfc_id, repo, proposed_by, proposed_at,
              graduated_at, graduated_by, owners_json, arbiters_json, tags_json,
-             models_json, funder_login, body, body_sha, last_entry_commit_at, updated_at)
-        VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, datetime('now'), datetime('now'))
-        ON CONFLICT(slug) DO UPDATE SET
+             models_json, funder_login, body, body_sha,
+             unreviewed, reviewed_at, reviewed_by, collection_id,
+             last_entry_commit_at, updated_at)
+        VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, datetime('now'), datetime('now'))
+        ON CONFLICT(collection_id, slug) DO UPDATE SET
             title = excluded.title,
             state = excluded.state,
             rfc_id = excluded.rfc_id,
@@ -105,6 +144,9 @@ def _upsert_cached_rfc(entry: entry_mod.Entry, body_sha: str) -> None:
             funder_login = excluded.funder_login,
             body = excluded.body,
             body_sha = excluded.body_sha,
+            unreviewed = excluded.unreviewed,
+            reviewed_at = excluded.reviewed_at,
+            reviewed_by = excluded.reviewed_by,
             last_entry_commit_at = datetime('now'),
             updated_at = datetime('now')
         """,
@@ -125,6 +167,10 @@ def _upsert_cached_rfc(entry: entry_mod.Entry, body_sha: str) -> None:
             funder_login,
             entry.body,
             body_sha,
+            1 if entry.unreviewed else 0,
+            entry.reviewed_at,
+            entry.reviewed_by,
+            collection_id,
         ),
     )
 
@@ -184,7 +230,7 @@ async def refresh_rfc_repo(config: Config, gitea: Gitea, slug: str) -> None:
             """
             INSERT INTO cached_branches (rfc_slug, branch_name, head_sha, state, last_commit_at)
             VALUES (?, ?, ?, 'open', ?)
-            ON CONFLICT(rfc_slug, branch_name) DO UPDATE SET
+            ON CONFLICT(collection_id, rfc_slug, branch_name) DO UPDATE SET
                 head_sha = excluded.head_sha,
                 state = CASE WHEN cached_branches.state = 'closed' THEN 'closed' ELSE 'open' END,
                 last_commit_at = excluded.last_commit_at
@@ -219,6 +265,19 @@ async def refresh_rfc_repo(config: Config, gitea: Gitea, slug: str) -> None:
         open_pulls, closed_pulls = [], []
     for pull in open_pulls + closed_pulls:
         head_branch = pull.get("head", {}).get("ref", "")
+        # Same deleted-branch recovery as refresh_meta_pulls: a merged-and-
+        # deleted PR's `head.ref` collapses to `refs/pull/<N>/head`. Here
+        # the slug is known (param), so state still updates correctly and
+        # no ghost forms — but blindly storing the sentinel would clobber
+        # the real branch name api_prs.py relies on as a fallback ref when
+        # the merge commit is gone. Recover it from the stored row.
+        if not head_branch or head_branch.startswith("refs/pull/"):
+            prior = db.conn().execute(
+                "SELECT head_branch FROM cached_prs WHERE repo = ? AND pr_number = ?",
+                (repo_full, pull["number"]),
+            ).fetchone()
+            if prior and prior["head_branch"]:
+                head_branch = prior["head_branch"]
         state = _state_from_pull(pull)
         gitea_opener = (pull.get("user") or {}).get("login") or ""
         opened_by = _resolve_actor(
@@ -307,7 +366,11 @@ async def refresh_meta_branches(config: Config, gitea: Gitea) -> None:
     structurally `edit/<slug>/<auto-name>` per §9.5, with dashes in place
     of slashes per the §19.2 path-routing candidate.
     """
-    org, repo = config.gitea_org, config.meta_repo
+    org = config.gitea_org
+    repo = projects_mod.default_content_repo(config)
+    if not repo:
+        log.warning("refresh_meta_branches: default project has no content_repo yet; skipping")
+        return
     try:
         branches = await gitea.list_branches(org, repo)
     except GiteaError as e:
@@ -329,16 +392,20 @@ async def refresh_meta_branches(config: Config, gitea: Gitea) -> None:
         if not slug:
             continue
         rfc = db.conn().execute(
-            "SELECT state FROM cached_rfcs WHERE slug = ?", (slug,)
+            "SELECT state, repo FROM cached_rfcs WHERE slug = ?", (slug,)
         ).fetchone()
-        if not rfc or rfc["state"] != "super-draft":
+        # Meta-only topology (§1): edit branches live on the meta repo for
+        # every meta-resident entry — super-drafts and active RFCs alike
+        # (active RFCs are graduated in place and keep editing here, §13).
+        # A legacy per-RFC repo (repo set) is the only thing excluded.
+        if not rfc or rfc["repo"] or rfc["state"] not in ("super-draft", "active"):
             continue
         edit_keys_seen.add((slug, name))
         db.conn().execute(
             """
             INSERT INTO cached_branches (rfc_slug, branch_name, head_sha, state, last_commit_at)
             VALUES (?, ?, ?, 'open', ?)
-            ON CONFLICT(rfc_slug, branch_name) DO UPDATE SET
+            ON CONFLICT(collection_id, rfc_slug, branch_name) DO UPDATE SET
                 head_sha = excluded.head_sha,
                 state = CASE WHEN cached_branches.state = 'closed' THEN 'closed' ELSE 'open' END,
                 last_commit_at = excluded.last_commit_at
@@ -352,14 +419,15 @@ async def refresh_meta_branches(config: Config, gitea: Gitea) -> None:
     # diverges from this single point.
     if meta_main_sha:
         super_drafts = db.conn().execute(
-            "SELECT slug FROM cached_rfcs WHERE state = 'super-draft'"
+            "SELECT slug FROM cached_rfcs "
+            "WHERE repo IS NULL AND state IN ('super-draft', 'active')"
         ).fetchall()
         for r in super_drafts:
             db.conn().execute(
                 """
                 INSERT INTO cached_branches (rfc_slug, branch_name, head_sha, state, last_commit_at)
                 VALUES (?, 'main', ?, 'open', ?)
-                ON CONFLICT(rfc_slug, branch_name) DO UPDATE SET
+                ON CONFLICT(collection_id, rfc_slug, branch_name) DO UPDATE SET
                     head_sha = excluded.head_sha,
                     last_commit_at = excluded.last_commit_at
                 """,
@@ -374,7 +442,8 @@ async def refresh_meta_branches(config: Config, gitea: Gitea) -> None:
         SELECT b.rfc_slug, b.branch_name
           FROM cached_branches b
           JOIN cached_rfcs r ON r.slug = b.rfc_slug
-         WHERE r.state = 'super-draft'
+         WHERE r.repo IS NULL
+           AND r.state IN ('super-draft', 'active')
            AND b.state != 'deleted'
            AND b.branch_name != 'main'
         """
@@ -418,19 +487,50 @@ async def refresh_meta_pulls(config: Config, gitea: Gitea) -> None:
     `On-behalf-of:` trailer from the PR body, then to the raw Gitea
     login as last resort.
     """
-    org, repo = config.gitea_org, config.meta_repo
+    org = config.gitea_org
+    bot_login = config.gitea_bot_user
+    rows = db.conn().execute(
+        "SELECT id, content_repo FROM projects WHERE content_repo IS NOT NULL AND content_repo != ''"
+    ).fetchall()
+    if not rows:
+        log.warning("refresh_meta_pulls: no projects with a content_repo yet; skipping")
+        return
+    for prow in rows:
+        await _refresh_project_pulls(org, prow["id"], prow["content_repo"], gitea, bot_login)
+
+
+async def _refresh_project_pulls(
+    org: str, project_id: str, repo: str, gitea: Gitea, bot_login: str
+) -> None:
     repo_full = f"{org}/{repo}"
     try:
         open_pulls = await gitea.list_pulls(org, repo, state="open")
         closed_pulls = await gitea.list_pulls(org, repo, state="closed")
     except GiteaError as e:
-        log.warning("refresh_meta_pulls: %s", e)
+        log.warning("refresh_meta_pulls: project %s: %s", project_id, e)
         return
 
-    bot_login = config.gitea_bot_user
-
     for pull in open_pulls + closed_pulls:
         head_branch = pull.get("head", {}).get("ref", "")
+        # A merged-and-deleted PR's branch is no longer reported by Gitea
+        # as its real name — the `head.ref` collapses to the synthetic
+        # `refs/pull/<N>/head` sentinel (or empty). The slug + kind both
+        # derive from the branch name, so a deleted branch would parse to
+        # slug=None and the row would be skipped forever, freezing the
+        # cached_prs row at its last-seen `state='open'` — a permanent
+        # ghost "pending idea" for an entry that has actually merged
+        # (caught when the operator authoring lane in ROADMAP #35 merged
+        # an idea PR with the branch deleted; the web UX leaves branches
+        # in place so it never tripped this). Recover the original branch
+        # from the row we already stored when the PR was open — that row
+        # retains the real `head_branch` (migration 002).
+        if not head_branch or head_branch.startswith("refs/pull/"):
+            prior = db.conn().execute(
+                "SELECT head_branch FROM cached_prs WHERE repo = ? AND pr_number = ?",
+                (repo_full, pull["number"]),
+            ).fetchone()
+            if prior and prior["head_branch"]:
+                head_branch = prior["head_branch"]
         slug = _slug_from_head_branch(head_branch)
         if slug is None:
             continue
@@ -464,8 +564,8 @@ async def refresh_meta_pulls(config: Config, gitea: Gitea) -> None:
             INSERT INTO cached_prs
                 (rfc_slug, pr_kind, repo, pr_number, title, description, state,
                  opened_by, opened_at, merged_at, closed_at,
-                 head_branch, base_branch, head_sha, merge_commit_sha)
-            VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
+                 head_branch, base_branch, head_sha, merge_commit_sha, project_id)
+            VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
             ON CONFLICT(repo, pr_number) DO UPDATE SET
                 title = excluded.title,
                 description = excluded.description,
@@ -492,6 +592,7 @@ async def refresh_meta_pulls(config: Config, gitea: Gitea) -> None:
                 (pull.get("base") or {}).get("ref") or "main",
                 (pull.get("head") or {}).get("sha"),
                 merge_commit_sha,
+                project_id,
             ),
         )
 
@@ -625,6 +726,10 @@ class Reconciler:
     async def sweep(self) -> None:
         log.info("reconciler: starting sweep")
         try:
+            try:
+                await registry_mod.refresh_registry(self._config, self._gitea)
+            except Exception:
+                log.exception("reconciler: registry refresh failed; keeping last-good projects")
             await refresh_meta_repo(self._config, self._gitea)
             await refresh_meta_branches(self._config, self._gitea)
             await refresh_meta_pulls(self._config, self._gitea)

backend/app/collections.py

@@ -0,0 +1,126 @@
+"""§22 collection grain — resolution helpers beneath the project tier.
+
+In S1 each project has exactly one collection (the default). These helpers
+recover the collection for a project and read the per-corpus fields (`type`,
+`initial_state`) that moved down from `projects` in migration 029. Project-grain
+authz (auth.py) recovers a row's project by joining `collections` on
+`collection_id`.
+"""
+from __future__ import annotations
+
+import json
+
+from . import db
+
+DEFAULT_COLLECTION_ID = "default"
+
+# §22.4a item (2): the displayed noun for an entry is a type-driven label, a
+# framework concept (like role names), not deployment content. The chrome reads
+# this from the API rather than hardcoding "RFC", so a `specification` collection
+# says "Spec" and a `bdd` collection says "Feature" with no per-deployment config.
+ENTRY_NOUN = {
+    "document": "RFC",
+    "specification": "Spec",
+    "bdd": "Feature",
+}
+_DEFAULT_ENTRY_NOUN = "RFC"
+
+
+def entry_noun(collection_type: str) -> str:
+    """The §22.4a entry noun for a collection type. Unknown types fall back to
+    the generic 'RFC' so a future type is never label-less."""
+    return ENTRY_NOUN.get(collection_type, _DEFAULT_ENTRY_NOUN)
+
+
+def _enabled_models_from_config(config_json: str | None) -> list[str] | None:
+    """§22.12 per-collection enabled_models from a `config_json` blob, or None
+    when unset (the collection inherits its project's universe)."""
+    if not config_json:
+        return None
+    try:
+        cfg = json.loads(config_json)
+    except (json.JSONDecodeError, TypeError):
+        return None
+    em = cfg.get("enabled_models") if isinstance(cfg, dict) else None
+    return [str(m) for m in em] if isinstance(em, list) else None
+
+
+def default_collection_id(project_id: str) -> str:
+    """The id of a project's default (S1: sole) collection. Falls back to the
+    literal 'default' when the project has no collection row yet."""
+    row = db.conn().execute(
+        "SELECT id FROM collections WHERE project_id = ? ORDER BY created_at, id LIMIT 1",
+        (project_id,),
+    ).fetchone()
+    return row["id"] if row else DEFAULT_COLLECTION_ID
+
+
+def project_of_collection(collection_id: str) -> str | None:
+    """The project a collection belongs to, or None if unknown."""
+    row = db.conn().execute(
+        "SELECT project_id FROM collections WHERE id = ?", (collection_id,)
+    ).fetchone()
+    return row["project_id"] if row else None
+
+
+def collection_initial_state(collection_id: str) -> str:
+    """§22.4b landing state for new entries in a collection. 'super-draft'
+    default for an unknown/unset row (today's safe flow)."""
+    row = db.conn().execute(
+        "SELECT initial_state FROM collections WHERE id = ?", (collection_id,)
+    ).fetchone()
+    if row is None or not row["initial_state"]:
+        return "super-draft"
+    return row["initial_state"]
+
+
+def collection_type(collection_id: str) -> str:
+    """The collection's immutable §22.4a type. 'document' default for unknown."""
+    row = db.conn().execute(
+        "SELECT type FROM collections WHERE id = ?", (collection_id,)
+    ).fetchone()
+    return row["type"] if row and row["type"] else "document"
+
+
+def subfolder_of(collection_id: str) -> str:
+    """The content-repo subfolder a collection lives under (§22.3). Empty string
+    for the default collection (entries at the repo root `rfcs/`)."""
+    row = db.conn().execute(
+        "SELECT subfolder FROM collections WHERE id = ?", (collection_id,)
+    ).fetchone()
+    return (row["subfolder"] if row else "") or ""
+
+
+def get_collection(collection_id: str) -> dict | None:
+    """The full collection row as a dict, or None if unknown. `enabled_models`
+    (§22.12) is unpacked from `config_json` as a list, or None when unset."""
+    row = db.conn().execute(
+        "SELECT id, project_id, type, subfolder, initial_state, visibility, name, "
+        "config_json FROM collections WHERE id = ?",
+        (collection_id,),
+    ).fetchone()
+    if row is None:
+        return None
+    out = dict(row)
+    out["enabled_models"] = _enabled_models_from_config(out.pop("config_json", None))
+    out["entry_noun"] = entry_noun(out["type"])
+    return out
+
+
+def list_collections(project_id: str, include_unlisted: bool = False) -> list[dict]:
+    """Collections in a project, the default first then by name (§22.5). `unlisted`
+    is omitted from enumeration unless include_unlisted (a direct-id read or the
+    corpus mirror, which serves every collection)."""
+    rows = db.conn().execute(
+        "SELECT id, project_id, type, subfolder, initial_state, visibility, name "
+        "FROM collections WHERE project_id = ? ORDER BY (id != 'default'), name, id",
+        (project_id,),
+    ).fetchall()
+    out: list[dict] = []
+    for r in rows:
+        if not include_unlisted and r["visibility"] == "unlisted":
+            continue
+        item = dict(r)
+        item["entry_noun"] = entry_noun(item["type"])
+        out.append(item)
+    return out

backend/app/config.py

@@ -32,7 +32,7 @@ class Config:
     gitea_bot_user: str
     gitea_bot_token: str
     gitea_org: str
-    meta_repo: str
+    registry_repo: str
     oauth_client_id: str
     oauth_client_secret: str
     app_url: str
@@ -44,14 +44,15 @@ class Config:
     anthropic_api_key: str = ""
     google_api_key: str = ""
     openai_api_key: str = ""
+    default_project_id: str = ""
 
     @property
     def redirect_uri(self) -> str:
         return f"{self.app_url}/auth/callback"
 
     @property
-    def meta_repo_full(self) -> str:
-        return f"{self.gitea_org}/{self.meta_repo}"
+    def registry_repo_full(self) -> str:
+        return f"{self.gitea_org}/{self.registry_repo}"
 
 
 def load_config() -> Config:
@@ -79,7 +80,7 @@ def load_config() -> Config:
         gitea_bot_user=_required("GITEA_BOT_USER"),
         gitea_bot_token=_required("GITEA_BOT_TOKEN"),
         gitea_org=_required("GITEA_ORG"),
-        meta_repo=_optional("META_REPO", "meta"),
+        registry_repo=_required("REGISTRY_REPO"),
         oauth_client_id=_required("OAUTH_CLIENT_ID"),
         oauth_client_secret=_required("OAUTH_CLIENT_SECRET"),
         app_url=_optional("APP_URL", "http://localhost:8000").rstrip("/"),
@@ -91,4 +92,5 @@ def load_config() -> Config:
         anthropic_api_key=_optional("ANTHROPIC_API_KEY"),
         google_api_key=_optional("GOOGLE_API_KEY"),
         openai_api_key=_optional("OPENAI_API_KEY"),
+        default_project_id=_optional("DEFAULT_PROJECT_ID"),
     )

backend/app/db.py

@@ -48,7 +48,29 @@ def run_migrations(config: Config) -> None:
             if version in applied:
                 continue
             sql = path.read_text()
-            conn.executescript("BEGIN; " + sql + "; COMMIT;")
+            if "-- migrate:no-foreign-keys" in sql:
+                # SQLite table rebuilds (changing a PRIMARY KEY / UNIQUE, e.g.
+                # folding project_id into a composite key) follow the official
+                # 12-step ALTER procedure, which requires FK enforcement OFF —
+                # and `PRAGMA foreign_keys` is a no-op *inside* a transaction, so
+                # it must be toggled here, around the script. The connection is
+                # in autocommit mode (isolation_level=None), so the PRAGMA takes
+                # effect immediately. We re-enable and run foreign_key_check
+                # after, failing the migration loudly if the rebuild left any
+                # dangling reference.
+                conn.execute("PRAGMA foreign_keys = OFF")
+                try:
+                    conn.executescript("BEGIN; " + sql + "; COMMIT;")
+                    violations = conn.execute("PRAGMA foreign_key_check").fetchall()
+                    if violations:
+                        raise RuntimeError(
+                            f"migration {version} left foreign-key violations: "
+                            f"{[tuple(v) for v in violations]}"
+                        )
+                finally:
+                    conn.execute("PRAGMA foreign_keys = ON")
+            else:
+                conn.executescript("BEGIN; " + sql + "; COMMIT;")
             conn.execute("INSERT INTO schema_migrations (version) VALUES (?)", (version,))
     finally:
         conn.close()

backend/app/device_trust.py

@@ -97,6 +97,13 @@ class IssueOutcome:
     raw_token: str
     row_id: int
 
+    @property
+    def cookie_value(self) -> str:
+        """The value to put in the `rfc_device_trust` cookie: the row-id
+        selector joined to the raw token (v0.25.0 / audit 0026 M1). The
+        selector lets `lookup` read one indexed row instead of scanning."""
+        return f"{self.row_id}.{self.raw_token}"
+
 
 def _new_token() -> str:
     return secrets.token_urlsafe(TOKEN_BYTES)
@@ -173,33 +180,37 @@ def lookup(raw_token: str) -> LookupOutcome:
     if not raw:
         return LookupOutcome(ok=False, user=None, reason="invalid")
 
-    # The unique index on `device_token_hash` would let us SELECT by
-    # hash if bcrypt were a stable hash, but bcrypt incorporates a
-    # per-row salt — equal tokens produce different hashes. We walk
-    # the candidate set instead. In practice the set is small (a
-    # human has a handful of trusted devices) and bcrypt is cheap on
-    # the order of milliseconds; the walk is bounded by the user's
-    # active device count.
+    # v0.25.0 (audit 0026 M1): the cookie is "<row_id>.<raw_token>". We
+    # parse the row-id selector and read exactly ONE row by its indexed
+    # primary key, then bcrypt-check the token against that single row.
     #
-    # We don't pre-filter by `revoked_at IS NULL` here so that a
-    # token presented for a recently-revoked row produces a
-    # 'revoked' outcome (the endpoint surfaces a different shape).
-    # Same for expired: we let the walk hit and classify after.
-    rows = db.conn().execute(
+    # The previous shape read EVERY device_trust row (all users, including
+    # revoked/expired) and bcrypt-checked each — an unauthenticated
+    # CPU-amplification DoS reachable at /auth/device-trust/start that
+    # grew without bound as the table accumulated. bcrypt's per-row salt
+    # is why we can't SELECT by hash; carrying the row-id in the cookie is
+    # the standard fix (the id is not secret; the token still is).
+    selector, sep, token = raw.partition(".")
+    if not sep or not selector.isdigit() or not token:
+        # Legacy bare-token cookies (pre-v0.25.0) and malformed values land
+        # here. We refuse rather than fall back to a full-table scan, so
+        # the amplification path is fully closed; affected users simply
+        # re-authenticate once via OTC/passcode and get a new cookie.
+        return LookupOutcome(ok=False, user=None, reason="invalid")
+
+    matched = db.conn().execute(
         """
         SELECT id, user_id, device_token_hash, expires_at, revoked_at
           FROM device_trust
-         ORDER BY id DESC
+         WHERE id = ?
         """,
-    ).fetchall()
+        (int(selector),),
+    ).fetchone()
 
-    matched = None
-    for row in rows:
-        if _check(raw, row["device_token_hash"]):
-            matched = row
-            break
-
-    if matched is None:
+    # One bcrypt check, against the selected row only. A wrong/forged token
+    # for a real id reads as 'unknown' (cookie cleared), same as a missing
+    # row — a probing client can't distinguish the two.
+    if matched is None or not _check(token, matched["device_token_hash"]):
         return LookupOutcome(ok=False, user=None, reason="unknown")
 
     if matched["revoked_at"] is not None:

backend/app/email_envelope.py

@@ -60,12 +60,17 @@ def build_envelope(
     `from_name` is the display label that goes through `formataddr`
     so spaces / commas in the display string are encoded correctly.
 
-    `body_plain` is mandatory. `body_html`, if supplied, lands as the
-    second part of a `multipart/alternative` body — mail clients
-    that prefer HTML render it; clients that don't fall back to the
-    plain part. The text/plain part comes first per RFC 2046, so a
-    plain-text client that picks the first body gets the readable
-    text.
+    `body_plain` is mandatory. `body_html` is **reserved and not yet
+    enabled** (security-audit-0026 I3): no send path supplies it today —
+    every rfc-app mail is plain text — and passing it raises
+    `NotImplementedError`. The parameter is kept in the signature for
+    documented future symmetry: when HTML mail is enabled it will land
+    as the second part of a `multipart/alternative` body (text/plain
+    first per RFC 2046, so a plain-text client picking the first part
+    still gets the readable text). Enabling it is a deliberate act — the
+    caller MUST HTML-escape any user content into `body_html` first (cf.
+    the C1 stored-XSS class: a mail client renders the HTML) and remove
+    the guard below in the same change.
 
     `reply_to`, when set, lets a send path point replies at a
     different mailbox than the From line (e.g., a watcher
@@ -131,13 +136,20 @@ def build_envelope(
             # idempotent and not require auth. See
             # `api_notifications.py` for the receiver.
             msg["List-Unsubscribe-Post"] = "List-Unsubscribe=One-Click"
-    if body_html:
-        # multipart/alternative: text/plain first, text/html second.
-        # `set_content` sets the first part (and the message's main
-        # body); `add_alternative` adds the second part and
-        # restructures the message as multipart/alternative.
-        msg.set_content(body_plain)
-        msg.add_alternative(body_html, subtype="html")
-    else:
-        msg.set_content(body_plain)
+    if body_html is not None:
+        # I3 (security-audit-0026): the multipart/alternative HTML path
+        # is intentionally NOT enabled. No send path passes `body_html`
+        # today, and emitting an HTML body built from user-supplied
+        # content without escaping it first would reintroduce the C1
+        # stored-XSS class in the mail channel (the recipient's client
+        # renders the HTML). Fail loudly here rather than silently
+        # shipping HTML: enabling HTML mail is a deliberate change that
+        # MUST HTML-escape user content at the call site and remove this
+        # guard together. The text/plain path below is the only live one.
+        raise NotImplementedError(
+            "HTML email is not enabled (security-audit-0026 I3): do not "
+            "pass body_html until user content is HTML-escaped at the "
+            "call site and this guard is intentionally removed."
+        )
+    msg.set_content(body_plain)
     return msg

backend/app/entry.py

@@ -30,7 +30,7 @@ _ABSENT = object()
 class Entry:
     slug: str
     title: str
-    state: str = "super-draft"  # super-draft | active | withdrawn
+    state: str = "super-draft"  # super-draft | active | withdrawn | retired (§3, §13.7)
     id: str | None = None       # 'RFC-NNNN' or None
     repo: str | None = None
     proposed_by: str = ""
@@ -50,6 +50,13 @@ class Entry:
     # operator credentials per §18 are used. The binding is inert until
     # the named user has a funder_consents row (the hybrid two-key rule).
     funder: str | None = None
+    # §22.4c: an `active` entry that landed without a human review gate
+    # carries unreviewed=True until an owner clears it. Orthogonal to
+    # `state`; only meaningful for active entries. reviewed_at/reviewed_by
+    # are the provenance of the clear, paralleling graduated_at/by.
+    unreviewed: bool = False
+    reviewed_at: str | None = None
+    reviewed_by: str | None = None
     body: str = ""
 
 
@@ -66,6 +73,7 @@ def parse(text: str) -> Entry:
         models = [str(m) for m in raw_models]
     raw_funder = fm.get("funder")
     funder = str(raw_funder).strip() if raw_funder else None
+    unreviewed = bool(fm.get("unreviewed") or False)
     return Entry(
         slug=str(fm.get("slug") or ""),
         title=str(fm.get("title") or ""),
@@ -81,6 +89,9 @@ def parse(text: str) -> Entry:
         tags=list(fm.get("tags") or []),
         models=models,
         funder=funder,
+        unreviewed=unreviewed,
+        reviewed_at=fm.get("reviewed_at") or None,
+        reviewed_by=fm.get("reviewed_by") or None,
         body=body,
     )
 
@@ -110,6 +121,14 @@ def serialize(entry: Entry) -> str:
     # second meaning here as with `models:`; one set of semantics.
     if entry.funder:
         fm["funder"] = entry.funder
+    # §22.4c: emit unreviewed only when True (a super-draft / reviewed
+    # active entry leaves the key absent → frontmatter stays minimal).
+    if entry.unreviewed:
+        fm["unreviewed"] = True
+    if entry.reviewed_at:
+        fm["reviewed_at"] = entry.reviewed_at
+    if entry.reviewed_by:
+        fm["reviewed_by"] = entry.reviewed_by
     yaml_text = yaml.safe_dump(fm, sort_keys=False, default_flow_style=False).rstrip()
     body = entry.body.lstrip("\n")
     if body:

backend/app/funder.py

@@ -220,7 +220,7 @@ def add_consent(user_id: int, slug: str) -> None:
     db.conn().execute(
         """
         INSERT INTO funder_consents (user_id, rfc_slug) VALUES (?, ?)
-        ON CONFLICT(user_id, rfc_slug) DO NOTHING
+        ON CONFLICT(collection_id, user_id, rfc_slug) DO NOTHING
         """,
         (user_id, slug),
     )

backend/app/hygiene.py

@@ -30,7 +30,7 @@ import logging
 import os
 from datetime import datetime, timedelta, timezone
 
-from . import db
+from . import db, projects as projects_mod
 from .bot import Bot
 from .config import Config
 
@@ -284,9 +284,10 @@ async def _delete_branch_via_bot(
     reason: str,
 ) -> bool:
     """Call `bot.delete_branch` with the system actor. Resolves the
-    `(org, repo)` pair from the slug: super-draft edit branches and
-    graduation branches live on the meta repo; active-RFC branches
-    live on the per-RFC repo named by `cached_rfcs.repo`.
+    `(org, repo)` pair from the slug: under the meta-only topology (§1)
+    every meta-resident entry's edit branches and graduation branches
+    live on the meta repo; a legacy per-RFC repo (a `repo:` that survives
+    from before the fold-back, §13.6) is named by `cached_rfcs.repo`.
 
     Returns True on a clean delete; False if the rfc row is missing
     (we leave the branch row in place — a subsequent reconciler sweep
@@ -297,12 +298,20 @@ async def _delete_branch_via_bot(
     if rfc is None:
         log.warning("hygiene: cannot delete %s/%s — slug missing from cache", slug, branch)
         return False
-    if rfc["state"] == "super-draft":
-        owner, repo = config.gitea_org, config.meta_repo
-    elif rfc["state"] == "active" and rfc["repo"] and "/" in rfc["repo"]:
+    if not rfc["repo"]:
+        repo = projects_mod.default_content_repo(config)
+        if not repo:
+            log.warning(
+                "hygiene: default project has no content_repo; skipping branch delete for %s/%s",
+                slug, branch,
+            )
+            return False
+        owner = config.gitea_org
+    elif "/" in rfc["repo"]:
         owner, repo = rfc["repo"].split("/", 1)
     else:
-        log.warning("hygiene: cannot resolve repo for %s state=%s", slug, rfc["state"])
+        log.warning("hygiene: cannot resolve repo for %s state=%s repo=%r",
+                    slug, rfc["state"], rfc["repo"])
         return False
     try:
         await bot.delete_branch(

backend/app/invites.py

@@ -144,10 +144,16 @@ def create_invite(
     The invitee `users` row is provisioned with:
       * `permission_state='granted'` — the admin's hand is the grant;
         the v0.8.0 self-serve `pending` queue is for the other path.
-      * `last_seen_at = NULL` — the discriminator for "invited but
-        not yet arrived" per the §16 / roadmap design. Every sign-in
-        path stamps `last_seen_at` to now, so a NULL value means the
-        invited user has not clicked through yet.
+      * `created_at` / `last_seen_at` — NOT set here, so both fall
+        through to the column default `datetime('now')` (the column is
+        `NOT NULL`; see `migrations/001_users_and_audit.sql` and the
+        longer note below). The "invited but not yet arrived" state is
+        therefore NOT carried on the user row — it is the existence of
+        an unclaimed `user_invite_tokens` row, surfaced as the listing's
+        `pending_invite` field. Consumers that want a truthful
+        last-seen MUST treat a pending-invite row as never-seen rather
+        than trusting `last_seen_at` (every real sign-in path stamps it
+        to now, but an unclaimed invite has never hit one).
       * `gitea_id = NULL`, `gitea_login = NULL` — same as a v0.7.0
         OTC-provisioned user; the OAuth identity is grandfathered if
         the user ever lands through that path.

backend/app/main.py

@@ -7,6 +7,7 @@ no need for a separate worker.
 from __future__ import annotations
 
 import logging
+import os
 import secrets
 from contextlib import asynccontextmanager
 
@@ -27,7 +28,10 @@ from . import (
     invites as invites_mod,
     otc,
     passcode as passcode_mod,
+    projects,
     providers as providers_mod,
+    ratelimit,
+    registry as registry_mod,
     turnstile,
     webhooks,
 )
@@ -98,6 +102,27 @@ async def lifespan(app: FastAPI):
     db.run_migrations(config)
     db.init(config)
     gitea = Gitea(config)
+    # §22.2: mirror the registry before anything reads projects/content_repo.
+    # First boot has no last-good rows, so a missing/invalid registry is fatal
+    # (loud-fail per separation-of-concerns); the reconciler sweep keeps it
+    # fresh thereafter and tolerates a later bad PR.
+    try:
+        await registry_mod.refresh_registry(config, gitea)
+    except Exception as e:
+        raise RuntimeError(
+            f"registry mirror failed at startup ({config.registry_repo_full}/projects.yaml): {e}"
+        ) from e
+    # §22.13 step 1: re-stamp the M1 bootstrap 'default' project id to the
+    # deployment's configured id (DEFAULT_PROJECT_ID) once the registry row
+    # exists, so the original corpus lands at a meaningful /p/<id>/ and
+    # 'default' is never a public URL. Idempotent no-op once done.
+    projects.restamp_default_project(config)
+    if projects.default_content_repo(config) is None:
+        raise RuntimeError(
+            f"registry does not describe the default project "
+            f"{projects.resolved_default_id(config)!r} (no content_repo). "
+            f"Add it to {config.registry_repo_full}/projects.yaml."
+        )
     bot = Bot(gitea)
     reconciler = cache.Reconciler(config, gitea)
     digest_sched = digest.DigestScheduler()
@@ -126,7 +151,7 @@ async def lifespan(app: FastAPI):
     reconciler.start()
     digest_sched.start()
     hygiene_sched.start()
-    log.info("RFC app started — meta repo %s/%s", config.gitea_org, config.meta_repo)
+    log.info("RFC app started — registry %s", config.registry_repo_full)
     try:
         yield
     finally:
@@ -142,12 +167,20 @@ def create_app() -> FastAPI:
     # eagerly via load_config(). Everything else waits for lifespan.
     config = load_config()
     app = FastAPI(lifespan=lifespan)
+    # v0.25.0 (audit 0026 M4): the session cookie is the primary 30-day
+    # auth credential and must carry `Secure` in production so it never
+    # travels cleartext. Default to Secure; a dev box serving over plain
+    # http opts out with SESSION_COOKIE_SECURE=false. Production (OHM is
+    # HTTPS-only with an HTTP->HTTPS 301) leaves this unset → Secure on.
+    session_secure = os.environ.get("SESSION_COOKIE_SECURE", "true").strip().lower() not in (
+        "0", "false", "no", "off",
+    )
     app.add_middleware(
         SessionMiddleware,
         secret_key=config.secret_key,
         session_cookie="rfc_session",
         max_age=60 * 60 * 24 * 30,
-        https_only=False,
+        https_only=session_secure,
     )
     return app
 
@@ -155,24 +188,25 @@ def create_app() -> FastAPI:
 app = create_app()
 
 
-def _set_device_trust_cookie(response: Response, raw_token: str) -> None:
+def _set_device_trust_cookie(response: Response, cookie_value: str) -> None:
     """Attach the v0.11.0 device-trust cookie to the response.
 
-    HttpOnly + Secure + SameSite=Lax + 30-day Max-Age + Path=/. The
-    cookie value is the raw token; server-side storage is the hash.
-    The cookie is "essential" per the v0.13.0 cookie-consent contract
-    (it is part of authentication), so we set it regardless of the
-    user's analytics / other-cookies choice.
+    HttpOnly + Secure + SameSite=Lax + 30-day Max-Age + Path=/. As of
+    v0.25.0 (audit 0026 M1) the value is `IssueOutcome.cookie_value` —
+    "<row_id>.<raw_token>" — so `device_trust.lookup` can read one indexed
+    row instead of scanning; server-side storage remains the bcrypt hash
+    of the token half only. The cookie is "essential" per the v0.13.0
+    cookie-consent contract (it is part of authentication), so we set it
+    regardless of the user's analytics / other-cookies choice.
 
-    Secure=True means the cookie is only ever sent over HTTPS. The
-    SessionMiddleware in `create_app` keeps `https_only=False` for
-    dev parity, but the device-trust cookie holds a 30-day credential
-    and must not travel cleartext — production deployments serve over
-    HTTPS, so Secure on the device-trust cookie is non-negotiable.
+    Secure=True means the cookie is only ever sent over HTTPS — the
+    device-trust cookie holds a 30-day credential and must never travel
+    cleartext. (The session cookie now also defaults to Secure; see M4 in
+    `create_app`.)
     """
     response.set_cookie(
         key=device_trust_mod.COOKIE_NAME,
-        value=raw_token,
+        value=cookie_value,
         max_age=device_trust_mod.COOKIE_MAX_AGE_SECONDS,
         path="/",
         secure=True,
@@ -245,6 +279,10 @@ def _oauth_router(config) -> APIRouter:
 
     @router.post("/auth/otc/request")
     async def otc_request(body: OtcRequestBody, request: Request):
+        # v0.25.0 (audit 0026 H1/L2): per-IP brake at the cheapest point,
+        # before the Turnstile network call or any bcrypt/SMTP work.
+        if not ratelimit.otc_request_limiter.allow(ratelimit.client_key(request)):
+            raise HTTPException(429, "Too many requests; please wait a few minutes")
         # v0.12.0 / roadmap item #10: gate the request on a successful
         # Turnstile siteverify before the bcrypt hash + SMTP send. The
         # check runs first so a failed challenge spends no rate budget
@@ -252,7 +290,7 @@ def _oauth_router(config) -> APIRouter:
         # secret AND TURNSTILE_REQUIRED=false (the default), the gate
         # opens — see `backend/app/turnstile.py` for the full matrix.
         client_ip = request.client.host if request.client else None
-        ts = turnstile.verify_token(body.turnstile_token, client_ip=client_ip)
+        ts = await turnstile.verify_token(body.turnstile_token, client_ip=client_ip)
         if not ts.ok:
             if ts.reason == "misconfigured":
                 # TURNSTILE_REQUIRED=true but the secret is unset. This
@@ -278,9 +316,25 @@ def _oauth_router(config) -> APIRouter:
 
     @router.post("/auth/otc/verify")
     async def otc_verify(body: OtcVerifyBody, request: Request, response: Response):
+        # v0.25.0 (audit 0026 H1): per-IP brake against fan-out guessing,
+        # plus the per-email lockout enforced inside otc.verify_code.
+        ip = ratelimit.client_key(request)
+        if not ratelimit.verify_limiter.allow(ip):
+            raise HTTPException(429, "Too many attempts; please wait a few minutes")
         result = otc.verify_code(body.email, body.code)
+        if result.reason == "locked":
+            raise HTTPException(
+                423,
+                {
+                    "detail": "Too many failed attempts; wait a few minutes or request a new code",
+                    "locked_until": result.locked_until,
+                },
+            )
         if not result.ok or result.user is None:
             raise HTTPException(400, "Invalid or expired code")
+        # Legit sign-in: clear this IP's window so a user who fat-fingered
+        # a couple of codes isn't left throttled.
+        ratelimit.verify_limiter.reset(ip)
         auth.store_session(request, result.user)
         # v0.8.0: surface `needs_profile` so the Login.jsx surface can
         # decide whether to advance to the first/last/why capture step
@@ -313,7 +367,7 @@ def _oauth_router(config) -> APIRouter:
         if body.trust_device:
             ua = request.headers.get("user-agent", "")
             outcome = device_trust_mod.issue(result.user.user_id, ua)
-            _set_device_trust_cookie(response, outcome.raw_token)
+            _set_device_trust_cookie(response, outcome.cookie_value)
         return {
             "ok": True,
             "user": {
@@ -337,12 +391,17 @@ def _oauth_router(config) -> APIRouter:
     # ---------------------------------------------------------------
 
     @router.get("/auth/passcode/check")
-    async def passcode_check(email: str = ""):
+    async def passcode_check(request: Request, email: str = ""):
         """Does this email have a passcode set? Anonymous endpoint —
         the Login.jsx flow calls this after the user types their email
         to decide whether to render a passcode input or fall back to
         OTC. We surface only the boolean; lockout state, the hash, and
-        the set-at stamp are not leaked here."""
+        the set-at stamp are not leaked here.
+
+        v0.25.0 (audit 0026 L3): per-IP rate limit so the has-passcode
+        boolean can't be bulk-harvested to enumerate accounts."""
+        if not ratelimit.check_limiter.allow(ratelimit.client_key(request)):
+            raise HTTPException(429, "Too many requests; please wait a few minutes")
         status = passcode_mod.passcode_status(email)
         return {"has_passcode": status.has_passcode}
 
@@ -376,6 +435,11 @@ def _oauth_router(config) -> APIRouter:
         v0.11.0: the body's `trust_device` flag, if true, mints a
         fresh device-trust row and sets the long-lived cookie. Same
         opt-in contract as `/auth/otc/verify`."""
+        # v0.25.0 (audit 0026 H1): per-IP brake in front of the per-account
+        # passcode lockout, so fan-out across emails is throttled too.
+        ip = ratelimit.client_key(request)
+        if not ratelimit.verify_limiter.allow(ip):
+            raise HTTPException(429, "Too many attempts; please wait a few minutes")
         result = passcode_mod.verify_passcode(body.email, body.passcode)
         if result.reason == "locked":
             raise HTTPException(
@@ -387,11 +451,12 @@ def _oauth_router(config) -> APIRouter:
             )
         if not result.ok or result.user is None:
             raise HTTPException(400, "Invalid passcode")
+        ratelimit.verify_limiter.reset(ip)
         auth.store_session(request, result.user)
         if body.trust_device:
             ua = request.headers.get("user-agent", "")
             outcome = device_trust_mod.issue(result.user.user_id, ua)
-            _set_device_trust_cookie(response, outcome.raw_token)
+            _set_device_trust_cookie(response, outcome.cookie_value)
         return {
             "ok": True,
             "user": {
@@ -459,7 +524,7 @@ def _oauth_router(config) -> APIRouter:
         if body.trust_device:
             ua = request.headers.get("user-agent", "")
             outcome = device_trust_mod.issue(result.user.user_id, ua)
-            _set_device_trust_cookie(response, outcome.raw_token)
+            _set_device_trust_cookie(response, outcome.cookie_value)
 
         # Has the user already set a passcode? (Could only happen via
         # an admin pre-population path that doesn't exist yet, but

backend/app/memberships.py

@@ -0,0 +1,141 @@
+"""§22 S4 (C.2) — scope-role grant operations over the `memberships` table.
+
+The membership *gates* (who may invite, who holds which role) live in
+`auth.py`; this module holds the *mutations* the invitation surface drives —
+granting, the "broader scope supersedes narrower" cleanup, listing, and
+revocation — mirroring how `invites.py` owns the create/claim/list of per-user
+invite tokens while the gate (`auth.can_invite_to_rfc`) lives in `auth.py`.
+
+The model (Part B / S3): a `memberships` row is `(scope_type ∈ {global,
+project, collection}, scope_id, user_id, role ∈ {owner, contributor})`, unique
+per `(scope_type, scope_id, user_id)`. A grant is a direct write of that row
+(the C.2 scenarios write the row immediately and §15-notify an existing
+account — there is no accept round-trip; inviting a not-yet-account email is
+out of S4 scope and handled by the admin-create-invite path).
+
+The "broader scope supersedes narrower" rule (C.2.6): granting a role at a
+broader scope removes this user's narrower rows that the new grant *subsumes*
+— a narrower row whose role is no more permissive than the new one. A narrower
+row that is *more* permissive is kept (no negative override: a child Owner
+grant survives a parent Contributor grant, and the §B.2 resolver still unions
+most-permissively).
+"""
+from __future__ import annotations
+
+from typing import Any
+
+from . import collections as collections_mod
+from . import db
+
+# Higher rank = more permissive. Used by the supersede rule: a narrower grant
+# is pruned only when its rank ≤ the new broader grant's rank.
+_ROLE_RANK = {"contributor": 1, "owner": 2}
+
+VALID_SCOPE_TYPES = ("global", "project", "collection")
+VALID_ROLES = ("owner", "contributor")
+GLOBAL_SCOPE_ID = "*"
+
+
+def user_by_email(email: str) -> dict[str, Any] | None:
+    """The `users` row (id, display_name, email, permission_state) for an
+    email, case-insensitively, or None. The grantee must already be an account
+    — S4 grants a scope role to an existing user, it does not provision one."""
+    row = db.conn().execute(
+        "SELECT id, display_name, email, permission_state, role "
+        "FROM users WHERE lower(email) = lower(?) "
+        "ORDER BY id LIMIT 1",
+        (email.strip(),),
+    ).fetchone()
+    return dict(row) if row else None
+
+
+def grant(
+    *,
+    scope_type: str,
+    scope_id: str,
+    user_id: int,
+    role: str,
+    granted_by: int | None,
+) -> None:
+    """Write (or update) the membership row, then apply the C.2.6
+    broader-scope-supersedes cleanup. Idempotent on `(scope_type, scope_id,
+    user_id)` — re-granting at the same scope updates the role and the grantor.
+
+    The grant is recorded regardless of the grantee's deployment
+    `permission_state`: a `pending` account's row is written (C.2.7), but the
+    §6 admission floor in `auth.effective_scope_role` keeps it conferring no
+    write until the account is granted at the deployment."""
+    db.conn().execute(
+        "INSERT INTO memberships (scope_type, scope_id, user_id, role, granted_by) "
+        "VALUES (?, ?, ?, ?, ?) "
+        "ON CONFLICT (scope_type, scope_id, user_id) "
+        "DO UPDATE SET role = excluded.role, granted_by = excluded.granted_by, "
+        "granted_at = datetime('now')",
+        (scope_type, scope_id, user_id, role, granted_by),
+    )
+    _prune_subsumed(scope_type=scope_type, scope_id=scope_id, user_id=user_id, role=role)
+
+
+def _prune_subsumed(*, scope_type: str, scope_id: str, user_id: int, role: str) -> None:
+    """Remove this user's narrower rows that the just-written broader grant
+    subsumes (same-or-lower role rank within the broader scope's subtree). A
+    collection grant subsumes nothing narrower (the per-entry tier is separate);
+    a project grant subsumes its collections; a global grant subsumes every
+    project and collection."""
+    rank = _ROLE_RANK[role]
+    keep_ranks = [r for r, v in _ROLE_RANK.items() if v <= rank]
+    if not keep_ranks:
+        return
+    placeholders = ",".join("?" for _ in keep_ranks)
+    if scope_type == "project":
+        # Narrower = collection-scope rows for collections in this project.
+        db.conn().execute(
+            f"DELETE FROM memberships "
+            f"WHERE user_id = ? AND scope_type = 'collection' "
+            f"  AND role IN ({placeholders}) "
+            f"  AND scope_id IN (SELECT id FROM collections WHERE project_id = ?)",
+            (user_id, *keep_ranks, scope_id),
+        )
+    elif scope_type == "global":
+        # Narrower = every project- and collection-scope row for this user.
+        db.conn().execute(
+            f"DELETE FROM memberships "
+            f"WHERE user_id = ? AND scope_type IN ('project', 'collection') "
+            f"  AND role IN ({placeholders})",
+            (user_id, *keep_ranks),
+        )
+
+
+def revoke(*, scope_type: str, scope_id: str, user_id: int) -> bool:
+    """Remove a membership row at exactly this scope. Returns True if a row was
+    removed. Revocation is scope-exact: it does not cascade to broader or
+    narrower grants (each is its own administrative act)."""
+    cur = db.conn().execute(
+        "DELETE FROM memberships WHERE scope_type = ? AND scope_id = ? AND user_id = ?",
+        (scope_type, scope_id, user_id),
+    )
+    return cur.rowcount > 0
+
+
+def list_for_project(project_id: str) -> list[dict[str, Any]]:
+    """Every project-scope grant on this project plus every collection-scope
+    grant on its collections, joined to the grantee's display fields — the data
+    behind the project-Owner membership panel. Ordered project grants first,
+    then by collection, then by role (Owner before Contributor)."""
+    rows = db.conn().execute(
+        """
+        SELECT m.scope_type, m.scope_id, m.user_id, m.role, m.granted_at,
+               u.display_name, u.email, u.permission_state,
+               c.name AS collection_name
+          FROM memberships m
+          JOIN users u ON u.id = m.user_id
+     LEFT JOIN collections c ON c.id = m.scope_id AND m.scope_type = 'collection'
+         WHERE (m.scope_type = 'project' AND m.scope_id = ?)
+            OR (m.scope_type = 'collection'
+                AND m.scope_id IN (SELECT id FROM collections WHERE project_id = ?))
+         ORDER BY (m.scope_type != 'project'), m.scope_id,
+                  CASE m.role WHEN 'owner' THEN 0 ELSE 1 END, u.display_name
+        """,
+        (project_id, project_id),
+    ).fetchall()
+    return [dict(r) for r in rows]

backend/app/models_resolver.py

@@ -38,22 +38,78 @@ from . import db, funder
 from .providers import BaseProvider
 
 
+def _models_from_config(config_json: str | None) -> list[str] | None:
+    """The `enabled_models` list inside a project/collection `config_json`,
+    or None when the key is absent (meaning "no narrowing at this tier")."""
+    if not config_json:
+        return None
+    try:
+        cfg = json.loads(config_json)
+    except (json.JSONDecodeError, TypeError):
+        return None
+    em = cfg.get("enabled_models") if isinstance(cfg, dict) else None
+    return [str(m) for m in em] if isinstance(em, list) else None
+
+
+def _narrow(universe: list[str], allowed: list[str] | None) -> list[str]:
+    """Intersect `universe` with `allowed`, preserving universe order. `allowed`
+    None means no narrowing at this tier; an empty list narrows to empty (an
+    opt-out), exactly like the §6.6 per-entry `models: []`."""
+    if allowed is None:
+        return universe
+    allow = set(allowed)
+    return [k for k in universe if k in allow]
+
+
+def _scope_narrowed_universe(
+    collection_id: str | None, operator_keys: list[str]
+) -> list[str]:
+    """§22.12 — narrow the operator (deployment) universe by the entry's
+    project then its collection `enabled_models`. Each tier may only narrow;
+    a missing config at a tier is a no-op. The collection cannot widen its
+    project because narrowing composes from the operator ceiling downward."""
+    if collection_id is None:
+        return list(operator_keys)
+    conn = db.conn()
+    crow = conn.execute(
+        "SELECT project_id, config_json FROM collections WHERE id = ?",
+        (collection_id,),
+    ).fetchone()
+    universe = list(operator_keys)
+    if crow is None:
+        return universe
+    prow = conn.execute(
+        "SELECT config_json FROM projects WHERE id = ?", (crow["project_id"],)
+    ).fetchone()
+    universe = _narrow(universe, _models_from_config(prow["config_json"] if prow else None))
+    universe = _narrow(universe, _models_from_config(crow["config_json"]))
+    return universe
+
+
 def resolve_models_for_rfc(
     slug: str, providers: dict[str, BaseProvider]
 ) -> list[str]:
-    """Return the per-RFC resolved model keys per §6.6, extended by §6.7.
+    """Return the per-RFC resolved model keys per §6.6, extended by §6.7 and
+    §22.12.
 
     The first entry is the RFC's default model. An empty list means
     AI is unavailable on this RFC and callers refuse the AI surface.
     """
-    # §6.7: the funder universe (if any) replaces the operator universe
-    # as the base set the §6.6 frontmatter intersects against.
-    funder_universe = funder.resolve_funder_universe(slug, providers)
-    base_universe = funder_universe if funder_universe is not None else list(providers.keys())
     row = db.conn().execute(
-        "SELECT models_json FROM cached_rfcs WHERE slug = ?",
+        "SELECT collection_id, models_json FROM cached_rfcs WHERE slug = ?",
         (slug,),
     ).fetchone()
+    collection_id = row["collection_id"] if row is not None else None
+    # §22.12: first narrow the operator universe by the entry's project +
+    # collection enabled_models (the deployment → project → collection chain).
+    scope_universe = _scope_narrowed_universe(collection_id, list(providers.keys()))
+    # §6.7: a consenting funder universe (if any) replaces the operator universe
+    # as the base set — still bounded by the §22.12 scope narrowing above.
+    funder_universe = funder.resolve_funder_universe(slug, providers)
+    if funder_universe is not None:
+        base_universe = _narrow(list(funder_universe), scope_universe)
+    else:
+        base_universe = scope_universe
     if row is None or row["models_json"] is None:
         return list(base_universe)
     try:

backend/app/notify.py

@@ -270,6 +270,217 @@ def fan_out_new_beta_request(
         )
 
 
+def fan_out_contribution_request(
+    *,
+    rfc_slug: str,
+    requester_user_id: int,
+    request_id: int,
+    matched_term: str,
+    who_i_am: str,
+    why: str,
+    use_case: str | None,
+) -> list[int]:
+    """Roadmap #28 Part 3: a reader asked to contribute to a pending
+    (super-draft) RFC. Land one actionable notification per owner and
+    return their ids (the caller stamps the first onto the request row as
+    the inbox-action handle).
+
+    Personal-direct: the owner is the named subject of the request, so the
+    §15.4 email gate consults `email_personal_direct` exactly as for the
+    other owner-facing personal events — no new preference column is
+    needed. The request's three free-text fields ride along in the payload
+    so the inbox row can show the full ask inline without a second fetch.
+    Actor is the requester per §15.9.
+    """
+    requester = db.conn().execute(
+        "SELECT display_name FROM users WHERE id = ?", (requester_user_id,)
+    ).fetchone()
+    display = (requester["display_name"] if requester else None) or "Someone"
+    details = {
+        "request_id": request_id,
+        "matched_term": matched_term,
+        "requester_user_id": requester_user_id,
+        "requester_display": display,
+        "who_i_am": who_i_am,
+        "why": why,
+        "use_case": use_case or "",
+    }
+    notif_ids: list[int] = []
+    for recipient_id in _entry_owner_user_ids(rfc_slug):
+        if recipient_id == requester_user_id:
+            continue
+        notif_ids.append(
+            _emit_one(
+                recipient_user_id=recipient_id,
+                event_kind="contribution_request_on_pending_rfc",
+                category=CATEGORY_PERSONAL,
+                actor_user_id=requester_user_id,
+                rfc_slug=rfc_slug,
+                branch_name=None,
+                pr_number=None,
+                details=details,
+            )
+        )
+    return notif_ids
+
+
+def notify_scope_role_granted(
+    *,
+    recipient_user_id: int,
+    granter_user_id: int | None,
+    scope_type: str,
+    scope_id: str,
+    role: str,
+    project_id: str | None,
+    project_name: str | None,
+    collection_name: str | None,
+) -> int | None:
+    """§22 S4 (C.2): a scope Owner granted `recipient` a role at a scope.
+    Personal-direct — the recipient is the named subject — so it rides the
+    `email_personal_direct` gate like the other owner-facing personal events.
+    The scope facts ride in the payload so the inbox row (and email body) names
+    the project and role without a second fetch. Actor is the granter (§15.9);
+    a system/administrative grant with no granter renders as "the app".
+
+    Returns the notification id, or None when the grantee would be notifying
+    themselves (a self-grant — no notification)."""
+    if granter_user_id is not None and recipient_user_id == granter_user_id:
+        return None
+    details = {
+        "scope_type": scope_type,
+        "scope_id": scope_id,
+        "role": role,
+        "project_id": project_id or "",
+        "project_name": project_name or "",
+        "collection_name": collection_name or "",
+    }
+    return _emit_one(
+        recipient_user_id=recipient_user_id,
+        event_kind="scope_role_granted",
+        category=CATEGORY_PERSONAL,
+        actor_user_id=granter_user_id,
+        rfc_slug=None,
+        branch_name=None,
+        pr_number=None,
+        details=details,
+    )
+
+
+def notify_contribution_decided(
+    *,
+    rfc_slug: str,
+    requester_user_id: int,
+    decider_user_id: int,
+    request_id: int,
+    accepted: bool,
+) -> None:
+    """Roadmap #28 Part 3: tell the requester an owner accepted or declined
+    their contribute request. On accept the requester also receives the
+    #12 invitation email out-of-band; this inbox row is the in-app echo
+    that points them at it."""
+    _emit_one(
+        recipient_user_id=requester_user_id,
+        event_kind=(
+            "contribution_request_accepted" if accepted else "contribution_request_declined"
+        ),
+        category=CATEGORY_PERSONAL,
+        actor_user_id=decider_user_id,
+        rfc_slug=rfc_slug,
+        branch_name=None,
+        pr_number=None,
+        details={"request_id": request_id},
+    )
+
+
+def fan_out_join_request(
+    *,
+    scope_type: str,
+    scope_id: str,
+    scope_name: str | None,
+    project_id: str | None,
+    project_name: str | None,
+    requester_user_id: int,
+    request_id: int,
+    requested_role: str,
+    message: str | None,
+) -> list[int]:
+    """§22.8: a user asked to join a scope. Land one actionable notification per
+    Owner across the scope's subtree (the cross-collection inbox, §22.11) and
+    return their ids (the caller stamps the first onto the request row as the
+    inbox-action handle — any of them can act on it).
+
+    Personal-direct: each Owner is a named subject able to act, so it rides the
+    `email_personal_direct` gate like the other owner-facing personal events. The
+    requested role + message ride in the payload so the inbox row shows the full
+    ask inline. Actor is the requester per §15.9.
+    """
+    requester = db.conn().execute(
+        "SELECT display_name FROM users WHERE id = ?", (requester_user_id,)
+    ).fetchone()
+    display = (requester["display_name"] if requester else None) or "Someone"
+    details = {
+        "request_id": request_id,
+        "scope_type": scope_type,
+        "scope_id": scope_id,
+        "scope_name": scope_name or scope_id,
+        "project_id": project_id or "",
+        "project_name": project_name or "",
+        "requested_role": requested_role,
+        "requester_user_id": requester_user_id,
+        "requester_display": display,
+        "message": message or "",
+    }
+    notif_ids: list[int] = []
+    for recipient_id in _scope_owner_user_ids(scope_type, scope_id):
+        if recipient_id == requester_user_id:
+            continue
+        notif_ids.append(
+            _emit_one(
+                recipient_user_id=recipient_id,
+                event_kind="join_request_on_scope",
+                category=CATEGORY_PERSONAL,
+                actor_user_id=requester_user_id,
+                rfc_slug=None,
+                branch_name=None,
+                pr_number=None,
+                details=details,
+            )
+        )
+    return notif_ids
+
+
+def notify_join_decided(
+    *,
+    requester_user_id: int,
+    decider_user_id: int,
+    request_id: int,
+    scope_type: str,
+    scope_id: str,
+    scope_name: str | None,
+    granted_role: str | None,
+    accepted: bool,
+) -> None:
+    """§22.8: tell the requester an Owner accepted (writing their `memberships`
+    row) or declined their request to join. The scope + granted role ride in the
+    payload so the inbox row names where they were let in without a second fetch."""
+    _emit_one(
+        recipient_user_id=requester_user_id,
+        event_kind=("join_request_accepted" if accepted else "join_request_declined"),
+        category=CATEGORY_PERSONAL,
+        actor_user_id=decider_user_id,
+        rfc_slug=None,
+        branch_name=None,
+        pr_number=None,
+        details={
+            "request_id": request_id,
+            "scope_type": scope_type,
+            "scope_id": scope_id,
+            "scope_name": scope_name or scope_id,
+            "granted_role": granted_role or "",
+        },
+    )
+
+
 def fan_out_chat_message(
     *,
     actor_user_id: int,
@@ -545,6 +756,41 @@ def _admin_user_ids() -> set[int]:
     }
 
 
+def _scope_owner_user_ids(scope_type: str, scope_id: str) -> set[int]:
+    """The Owners who administer a scope *across the subtree* (§22.8 / §22.11) —
+    the recipients of a request-to-join, aggregated upward so the request reaches
+    everyone who could grant it. For a `collection`: its collection-scope Owners,
+    its project's Owners, the global Owners, and deployment owners/admins. For a
+    `project`: its project-scope Owners plus global Owners and deployment
+    owners/admins. (Mirrors the upward fold in `auth.can_invite_at_*`.)"""
+    # Deployment owners/admins are global Owners by §B.1; explicit
+    # scope_type='global' Owner grants join them.
+    ids: set[int] = set(_admin_user_ids())
+    for r in db.conn().execute(
+        "SELECT user_id AS id FROM memberships WHERE scope_type = 'global' AND role = 'owner'"
+    ):
+        ids.add(r["id"])
+
+    def _owners_at(stype: str, sid: str) -> None:
+        for r in db.conn().execute(
+            "SELECT user_id AS id FROM memberships "
+            "WHERE scope_type = ? AND scope_id = ? AND role = 'owner'",
+            (stype, sid),
+        ):
+            ids.add(r["id"])
+
+    if scope_type == "collection":
+        _owners_at("collection", scope_id)
+        prow = db.conn().execute(
+            "SELECT project_id FROM collections WHERE id = ?", (scope_id,)
+        ).fetchone()
+        if prow and prow["project_id"]:
+            _owners_at("project", prow["project_id"])
+    elif scope_type == "project":
+        _owners_at("project", scope_id)
+    return ids
+
+
 def _proposer_user_id(rfc_slug: str) -> set[int]:
     row = db.conn().execute(
         """
@@ -769,6 +1015,46 @@ def render_summary(event_kind: str, actor_display: str | None, rfc_title: str |
         return f"{actor} began graduating {title}."
     if event_kind == "pr_conflict_with_main":
         return f"{actor} started a resolution branch on {title}."
+    if event_kind == "contribution_request_on_pending_rfc":
+        # Roadmap #28 Part 3: owner-facing, actionable. The term is the
+        # super-draft reference that surfaced the offer; the inbox row
+        # renders Accept/Decline beneath this line.
+        term = extras.get("matched_term") or title
+        return f"{actor} wants to contribute to your pending RFC for '{term}'."
+    if event_kind == "contribution_request_accepted":
+        return f"{actor} accepted your request to contribute to {title} — check your email to accept the invitation."
+    if event_kind == "contribution_request_declined":
+        return f"{actor} declined your request to contribute to {title}."
+    if event_kind == "scope_role_granted":
+        # §22 S4 (C.2): names the role and the scope (the project, and the
+        # collection when collection-scoped) per "a §15 notification naming the
+        # project and role".
+        role_label = "Owner" if extras.get("role") == "owner" else "RFC Contributor"
+        project_label = extras.get("project_name") or extras.get("project_id") or "a project"
+        scope_type = extras.get("scope_type")
+        if scope_type == "collection":
+            col_label = extras.get("collection_name") or extras.get("scope_id") or "a collection"
+            return f"{actor} granted you {role_label} on collection {project_label}/{col_label}."
+        if scope_type == "global":
+            return f"{actor} granted you {role_label} across the whole deployment."
+        return f"{actor} granted you {role_label} on project {project_label}."
+    if event_kind == "join_request_on_scope":
+        # §22.8: owner-facing, actionable. Names who wants in, where, and as
+        # what; the inbox row renders Accept/Decline beneath this line.
+        role_label = "Owner" if extras.get("requested_role") == "owner" else "RFC Contributor"
+        scope_type = extras.get("scope_type")
+        scope_label = extras.get("scope_name") or extras.get("scope_id") or "a scope"
+        where = (
+            f"collection {scope_label}" if scope_type == "collection" else f"project {scope_label}"
+        )
+        return f"{actor} asked to join {where} as {role_label}."
+    if event_kind == "join_request_accepted":
+        role_label = "Owner" if extras.get("granted_role") == "owner" else "RFC Contributor"
+        scope_label = extras.get("scope_name") or extras.get("scope_id") or "the scope"
+        return f"{actor} accepted your request to join {scope_label} — you're in as {role_label}."
+    if event_kind == "join_request_declined":
+        scope_label = extras.get("scope_name") or extras.get("scope_id") or "the scope"
+        return f"{actor} declined your request to join {scope_label}."
     if event_kind == "new_beta_request":
         # v0.9.0: framework-scoped, not RFC-scoped. The actor (the
         # requester) and the captured full name + email read as
@@ -884,6 +1170,11 @@ def list_inbox(
             "read_at": row["read_at"],
             "category": extras.get("category"),
             "summary": render_summary(row["event_kind"], row["actor_display"], row["rfc_title"], extras),
+            # The row's payload, surfaced for kinds that render inline
+            # detail (e.g. #28 Part 3's contribute-request who/why/use-case
+            # + Accept/Decline). Safe to expose: a recipient only ever sees
+            # their own notifications.
+            "extras": extras,
         })
 
     if bundled:

backend/app/otc.py

@@ -85,6 +85,15 @@ def _cooldown_seconds() -> int:
         return 60
 
 
+# v0.25.0 / security audit 0026 (H1): per-email OTC verify lockout,
+# mirroring the passcode path (passcode.py). Five consecutive wrong codes
+# for an email lock its OTC verify for 15 minutes. The per-IP limiter in
+# ratelimit.py is the primary brute-force brake; this is the durable,
+# passcode-parity layer.
+LOCKOUT_AFTER_FAILED_ATTEMPTS = 5
+LOCKOUT_DURATION_MINUTES = 15
+
+
 # ---------------------------------------------------------------------------
 # Code generation + hashing
 # ---------------------------------------------------------------------------
@@ -206,6 +215,61 @@ class VerifyOutcome:
     ok: bool
     user: SessionUser | None
     reason: str
+    # v0.25.0 (H1): ISO-8601 stamp when reason == 'locked'.
+    locked_until: str | None = None
+
+
+def _verify_lockout_until(email: str) -> str | None:
+    """Return the active lockout stamp for `email`, or None if not locked.
+
+    Clears an elapsed lockout (and resets the counter) as a side effect so
+    the next failure starts a fresh budget — mirrors passcode.verify_passcode.
+    """
+    row = db.conn().execute(
+        "SELECT failed_attempts, locked_until FROM otc_verify_state WHERE email = ?",
+        (email,),
+    ).fetchone()
+    if row is None or not row["locked_until"]:
+        return None
+    still_locked = db.conn().execute(
+        "SELECT datetime(?) > datetime('now') AS locked", (row["locked_until"],),
+    ).fetchone()["locked"]
+    if still_locked:
+        return row["locked_until"]
+    db.conn().execute(
+        "UPDATE otc_verify_state SET failed_attempts = 0, locked_until = NULL WHERE email = ?",
+        (email,),
+    )
+    return None
+
+
+def _record_verify_failure(email: str) -> None:
+    """Increment the per-email failure counter; stamp a lockout once it
+    crosses the threshold. Mirrors the passcode lockout shape."""
+    db.conn().execute(
+        """
+        INSERT INTO otc_verify_state (email, failed_attempts)
+        VALUES (?, 1)
+        ON CONFLICT(email) DO UPDATE SET failed_attempts = failed_attempts + 1
+        """,
+        (email,),
+    )
+    count = db.conn().execute(
+        "SELECT failed_attempts FROM otc_verify_state WHERE email = ?", (email,),
+    ).fetchone()["failed_attempts"]
+    if count >= LOCKOUT_AFTER_FAILED_ATTEMPTS:
+        db.conn().execute(
+            f"""
+            UPDATE otc_verify_state
+               SET locked_until = datetime('now', '+{LOCKOUT_DURATION_MINUTES} minutes')
+             WHERE email = ?
+            """,
+            (email,),
+        )
+
+
+def _clear_verify_state(email: str) -> None:
+    db.conn().execute("DELETE FROM otc_verify_state WHERE email = ?", (email,))
 
 
 def verify_code(email: str, code: str) -> VerifyOutcome:
@@ -214,6 +278,13 @@ def verify_code(email: str, code: str) -> VerifyOutcome:
     if not email or not code:
         return VerifyOutcome(ok=False, user=None, reason="invalid")
 
+    # v0.25.0 (H1): refuse before spending any bcrypt if this email is in
+    # its OTC-verify lockout window. The passcode path is unaffected — a
+    # locked-out OTC user can still set/use a passcode, and vice versa.
+    locked_until = _verify_lockout_until(email)
+    if locked_until:
+        return VerifyOutcome(ok=False, user=None, reason="locked", locked_until=locked_until)
+
     rows = db.conn().execute(
         """
         SELECT id, code_hash, expires_at, consumed_at
@@ -237,6 +308,9 @@ def verify_code(email: str, code: str) -> VerifyOutcome:
             break
 
     if matched is None:
+        # A genuine wrong guess against this email — the brute-force
+        # signal. Count it toward the lockout threshold (H1).
+        _record_verify_failure(email)
         return VerifyOutcome(ok=False, user=None, reason="wrong")
 
     if matched["consumed_at"] is not None:
@@ -255,6 +329,8 @@ def verify_code(email: str, code: str) -> VerifyOutcome:
         "UPDATE otc_codes SET consumed_at = datetime('now') WHERE id = ?",
         (matched["id"],),
     )
+    # Success wipes the per-email failure counter (H1).
+    _clear_verify_state(email)
     user = provision_or_link_user(email)
     return VerifyOutcome(ok=True, user=user, reason="ok")
 

backend/app/projects.py

@@ -0,0 +1,122 @@
+"""Project registry — the §22 multi-project layer.
+
+A deployment hosts one or more projects (§22.1). The git registry mirror
+that lets a deployment declare projects lands in M3 and drives this module.
+`seed_default_project` (the §22.13 META_REPO backfill) is retired in M3;
+the registry mirror (`registry.refresh_registry`) is authoritative.
+"""
+from __future__ import annotations
+
+import logging
+
+from . import db
+from .config import Config
+
+log = logging.getLogger(__name__)
+
+DEFAULT_PROJECT_ID = "default"
+
+
+def resolved_default_id(config: Config) -> str:
+    """The id of the deployment's bootstrap/default project. Plan A: always
+    'default' (the re-stamp to a config slug rides Plan B). The config knob is
+    read here so Plan B can flip the resolution without touching call sites."""
+    return config.default_project_id.strip() or DEFAULT_PROJECT_ID
+
+
+def restamp_default_project(config: Config) -> None:
+    """§22.13 step 1 — one-time rename of the M1 bootstrap project id
+    (DEFAULT_PROJECT_ID = 'default') to the deployment's configured default id
+    (the DEFAULT_PROJECT_ID env var, e.g. 'ohm'), so the deployment's original
+    corpus lands at a meaningful `/p/<id>/` and `default` is never a public URL.
+
+    Renames `project_id` across every project-scoped table (discovered by
+    column, so it stays correct as the schema grows), then drops the stale
+    bootstrap `projects` row (its data has moved to the configured row, which
+    the registry mirror already created). Idempotent and a no-op when the
+    configured id is still 'default' or no bootstrap rows remain. Runs at
+    startup after the registry mirror, with FK enforcement off for the rename
+    (the composite FKs are kept consistent because parent and child rows are
+    renamed together) and a foreign_key_check backstop before commit.
+    """
+    target = resolved_default_id(config)
+    if target == DEFAULT_PROJECT_ID:
+        return
+    conn = db.conn()
+    # §22 three-tier: the entry-corpus tables key on collection_id now; detect a
+    # lingering bootstrap project by the project-grain `collections.project_id`
+    # (the PRAGMA scan below still renames every project_id column dynamically).
+    has_rows = conn.execute(
+        "SELECT 1 FROM collections WHERE project_id = ? LIMIT 1", (DEFAULT_PROJECT_ID,)
+    ).fetchone()
+    stale_proj = conn.execute(
+        "SELECT 1 FROM projects WHERE id = ? LIMIT 1", (DEFAULT_PROJECT_ID,)
+    ).fetchone()
+    if not has_rows and not stale_proj:
+        return
+    if conn.execute("SELECT 1 FROM projects WHERE id = ? LIMIT 1", (target,)).fetchone() is None:
+        log.warning("restamp: target project %r not in registry yet; skipping", target)
+        return
+
+    tables = [r["name"] for r in conn.execute("SELECT name FROM sqlite_master WHERE type='table'")]
+    pid_tables = [
+        t for t in tables
+        if any(c["name"] == "project_id" for c in conn.execute(f"PRAGMA table_info({t})"))
+    ]
+    conn.execute("PRAGMA foreign_keys = OFF")
+    try:
+        conn.execute("BEGIN")
+        for t in pid_tables:
+            conn.execute(
+                f"UPDATE {t} SET project_id = ? WHERE project_id = ?",
+                (target, DEFAULT_PROJECT_ID),
+            )
+        # The bootstrap row's data has moved to the configured (registry) row.
+        conn.execute("DELETE FROM projects WHERE id = ?", (DEFAULT_PROJECT_ID,))
+        violations = conn.execute("PRAGMA foreign_key_check").fetchall()
+        if violations:
+            conn.execute("ROLLBACK")
+            raise RuntimeError(
+                f"restamp left foreign-key violations: {[tuple(v) for v in violations]}"
+            )
+        conn.execute("COMMIT")
+    except Exception:
+        try:
+            conn.execute("ROLLBACK")
+        except Exception:
+            pass
+        raise
+    finally:
+        conn.execute("PRAGMA foreign_keys = ON")
+    log.info("restamp: renamed bootstrap project %r -> %r across %d tables",
+             DEFAULT_PROJECT_ID, target, len(pid_tables))
+
+
+def default_content_repo(config: Config) -> str | None:
+    """The content repo the single-corpus mirror reads, from the default
+    project's row (filled by the registry mirror). Replaces the retired
+    META_REPO. None until the registry mirror has run."""
+    row = db.conn().execute(
+        "SELECT content_repo FROM projects WHERE id = ?",
+        (resolved_default_id(config),),
+    ).fetchone()
+    return row["content_repo"] if row and row["content_repo"] else None
+
+
+def content_repo(project_id: str) -> str | None:
+    """The content repo for a specific project (§22.3). None if unknown/unset.
+    The per-project successor to `default_content_repo` for the write path."""
+    row = db.conn().execute(
+        "SELECT content_repo FROM projects WHERE id = ?", (project_id,)
+    ).fetchone()
+    return row["content_repo"] if row and row["content_repo"] else None
+
+
+def project_initial_state(project_id: str) -> str:
+    """§22.4b landing state for new entries in a project's default collection
+    (the per-corpus field moved down to the collection in migration 029).
+    Defaults to 'super-draft' for an unknown/unset row (today's-flow default)."""
+    from . import collections as collections_mod
+    return collections_mod.collection_initial_state(
+        collections_mod.default_collection_id(project_id)
+    )

backend/app/ratelimit.py

@@ -0,0 +1,92 @@
+"""In-process per-IP sliding-window rate limiter (security audit 0026, H1).
+
+The auth verify endpoints (`/auth/otc/verify`, `/auth/passcode/verify`)
+had no per-IP brake, so an attacker could fan out guesses against a
+target identity bounded only by bcrypt cost. This module is the brake.
+
+It is deliberately tiny: §4.2 says the app is a single process with a
+colocated SQLite file, so an in-memory dict of `key -> deque[timestamps]`
+is sufficient and needs no shared store. State resets on restart, which
+fails *open* for a brief window — acceptable because the per-email OTC
+lockout (`otc_verify_state`) and the passcode lockout both persist in the
+database and carry the durable guarantee; this limiter is the
+anti-fan-out layer on top.
+
+Chosen over a per-identity lockout *as the primary control* because a
+per-IP window throttles the attacker without letting them grief a victim
+by locking that victim's account (the known downside of identity
+lockouts). Both layers run together.
+"""
+from __future__ import annotations
+
+import threading
+import time
+from collections import defaultdict, deque
+
+
+class SlidingWindowLimiter:
+    """Allow at most `max_events` per `window_seconds` per key.
+
+    `allow(key)` records an event and returns True if the key is still
+    within budget, False if it has exceeded it. Timestamps use a
+    monotonic clock so the limiter is immune to wall-clock jumps.
+    """
+
+    def __init__(self, max_events: int, window_seconds: float) -> None:
+        self.max_events = max_events
+        self.window_seconds = window_seconds
+        self._events: dict[str, deque[float]] = defaultdict(deque)
+        self._lock = threading.Lock()
+
+    def allow(self, key: str) -> bool:
+        now = time.monotonic()
+        cutoff = now - self.window_seconds
+        with self._lock:
+            q = self._events[key]
+            while q and q[0] < cutoff:
+                q.popleft()
+            if len(q) >= self.max_events:
+                return False
+            q.append(now)
+            # Opportunistic cleanup so idle keys don't accumulate forever.
+            if not q:
+                self._events.pop(key, None)
+            return True
+
+    def reset(self, key: str) -> None:
+        """Drop a key's window — e.g. after a successful sign-in so a
+        legitimate user who fat-fingered a few times isn't throttled."""
+        with self._lock:
+            self._events.pop(key, None)
+
+
+# Module-level limiters shared across requests (one process, so module
+# state is the natural home). Tunables are intentionally generous enough
+# not to bother a human retyping a code, tight enough to kill fan-out:
+#   * verify: 10 attempts / 5 min / IP across the auth verify surfaces.
+#   * otc request: 5 sends / 5 min / IP (Turnstile is the primary gate;
+#     this is defense in depth against a solved-challenge replay loop).
+verify_limiter = SlidingWindowLimiter(max_events=10, window_seconds=300)
+otc_request_limiter = SlidingWindowLimiter(max_events=5, window_seconds=300)
+# /auth/passcode/check is an anonymous has-passcode oracle (audit 0026 L3).
+# It's a legitimate Login-flow affordance, so the budget is generous —
+# enough for a human typing emails, tight enough to stop bulk scraping.
+check_limiter = SlidingWindowLimiter(max_events=30, window_seconds=300)
+
+
+def _reset_all_for_tests() -> None:
+    """Clear every module-level limiter's window. Test support only — the
+    limiters are process-global singletons, so without a per-test reset
+    one test's requests bleed into the next and later tests trip the
+    budget (429). Not called in production."""
+    for lim in (verify_limiter, otc_request_limiter, check_limiter):
+        with lim._lock:
+            lim._events.clear()
+
+
+def client_key(request) -> str:
+    """Best-effort client identity for limiting. Behind nginx the app is
+    started with `--forwarded-allow-ips 127.0.0.1`, so `request.client.host`
+    reflects the real client IP via Uvicorn's ProxyHeaders handling."""
+    client = getattr(request, "client", None)
+    return client.host if client and client.host else "unknown"

backend/app/registry.py

@@ -0,0 +1,350 @@
+"""§22.2 project registry mirror — the config-side analogue of
+cache.refresh_meta_repo.
+
+A deployment declares its projects in a `projects.yaml` at the root of
+REGISTRY_REPO. This module mirrors that file into the `projects` cache table
+and the `deployment` singleton. Per §22.2, `projects` rows flow from the
+registry only — never from user actions. The mirror runs on the registry-repo
+webhook and on every reconciler sweep (Option A wiring, Task 5).
+"""
+from __future__ import annotations
+
+import base64
+import json
+import logging
+import re
+from dataclasses import dataclass, field
+
+import yaml
+
+from . import db
+from .config import Config
+from .gitea import Gitea
+
+log = logging.getLogger(__name__)
+
+VALID_TYPES = {"document", "specification", "bdd"}
+VALID_VISIBILITY = {"gated", "public", "unlisted"}
+VALID_INITIAL_STATE = {"super-draft", "active"}
+# §22.4b: per-type default landing state.
+_TYPE_DEFAULT_INITIAL_STATE = {
+    "document": "super-draft",
+    "specification": "super-draft",
+    "bdd": "active",
+}
+_SLUG_RE = re.compile(r"^[a-z0-9](?:[a-z0-9-]*[a-z0-9])?$")
+
+
+class RegistryError(Exception):
+    """A registry document that fails validation, or a missing registry file.
+
+    Raised by parse_registry/refresh_registry. The caller decides severity:
+    fatal at startup (no last-good to serve), tolerated on a running deployment
+    (keep the last-good projects rows). See Task 5 wiring.
+    """
+
+
+@dataclass
+class ProjectEntry:
+    id: str
+    name: str
+    type: str
+    content_repo: str
+    visibility: str
+    initial_state: str
+    config: dict = field(default_factory=dict)  # theme, enabled_models
+
+
+@dataclass
+class CollectionEntry:
+    """A named collection declared by a `.collection.yaml` manifest inside a
+    project's content repo (S2). `visibility=None` means "inherit the project's
+    visibility"."""
+    type: str
+    visibility: str | None
+    initial_state: str
+    name: str | None
+    config: dict = field(default_factory=dict)  # §22.12 enabled_models
+
+
+@dataclass
+class RegistryDoc:
+    deployment_name: str
+    deployment_tagline: str
+    projects: list[ProjectEntry]
+
+
+def parse_registry(text: str) -> RegistryDoc:
+    """Parse + validate projects.yaml. Pure (no I/O). Raises RegistryError."""
+    raw = yaml.safe_load(text) or {}
+    dep = raw.get("deployment") or {}
+    projects_raw = raw.get("projects") or []
+    if not isinstance(projects_raw, list) or not projects_raw:
+        raise RegistryError("registry must declare at least one project")
+    seen: set[str] = set()
+    entries: list[ProjectEntry] = []
+    for p in projects_raw:
+        if not isinstance(p, dict):
+            raise RegistryError(f"each project entry must be a mapping, got {type(p).__name__}")
+        pid = str(p.get("id") or "").strip()
+        if not _SLUG_RE.match(pid):
+            raise RegistryError(f"project id {pid!r} is not a valid slug")
+        if pid in seen:
+            raise RegistryError(f"duplicate project id {pid!r}")
+        seen.add(pid)
+        name = str(p.get("name") or "").strip()
+        if not name:
+            raise RegistryError(f"project {pid!r} missing name")
+        ptype = str(p.get("type") or "").strip()
+        if ptype not in VALID_TYPES:
+            raise RegistryError(f"project {pid!r} has invalid type {ptype!r}")
+        content_repo = str(p.get("content_repo") or "").strip()
+        if not content_repo:
+            raise RegistryError(f"project {pid!r} missing content_repo")
+        vis = str(p.get("visibility") or "gated").strip()
+        if vis not in VALID_VISIBILITY:
+            raise RegistryError(f"project {pid!r} has invalid visibility {vis!r}")
+        initial_state = str(
+            p.get("initial_state") or _TYPE_DEFAULT_INITIAL_STATE[ptype]
+        ).strip()
+        if initial_state not in VALID_INITIAL_STATE:
+            raise RegistryError(
+                f"project {pid!r} has invalid initial_state {initial_state!r}"
+            )
+        cfg: dict = {}
+        if p.get("theme") is not None:
+            cfg["theme"] = p["theme"]
+        if p.get("enabled_models") is not None:
+            cfg["enabled_models"] = [str(m) for m in p["enabled_models"]]
+        entries.append(
+            ProjectEntry(pid, name, ptype, content_repo, vis, initial_state, cfg)
+        )
+    return RegistryDoc(
+        deployment_name=str(dep.get("name") or "").strip(),
+        deployment_tagline=str(dep.get("tagline") or "").strip(),
+        projects=entries,
+    )
+
+
+def parse_collection_manifest(text: str) -> CollectionEntry:
+    """Parse + validate a `.collection.yaml`. Pure (no I/O). Raises RegistryError.
+
+    `type` is required and immutable (§22.4a, enforced at upsert). `visibility`
+    is optional — omitted means inherit the project's. `initial_state` defaults
+    per type (§22.4b)."""
+    raw = yaml.safe_load(text) or {}
+    if not isinstance(raw, dict):
+        raise RegistryError("collection manifest must be a mapping")
+    ctype = str(raw.get("type") or "").strip()
+    if ctype not in VALID_TYPES:
+        raise RegistryError(f"collection has invalid type {ctype!r}")
+    vis = raw.get("visibility")
+    if vis is not None:
+        vis = str(vis).strip()
+        if vis not in VALID_VISIBILITY:
+            raise RegistryError(f"collection has invalid visibility {vis!r}")
+    initial_state = str(
+        raw.get("initial_state") or _TYPE_DEFAULT_INITIAL_STATE[ctype]
+    ).strip()
+    if initial_state not in VALID_INITIAL_STATE:
+        raise RegistryError(f"collection has invalid initial_state {initial_state!r}")
+    name = raw.get("name")
+    name = str(name).strip() if name else None
+    # §22.12: an optional per-collection enabled_models list that narrows the
+    # project's universe. Absent → no narrowing (inherit). Present (incl. empty)
+    # → narrowing applies; [] opts the collection out of AI.
+    cfg: dict = {}
+    if raw.get("enabled_models") is not None:
+        em = raw["enabled_models"]
+        if not isinstance(em, list):
+            raise RegistryError("collection enabled_models must be a list")
+        cfg["enabled_models"] = [str(m) for m in em]
+    return CollectionEntry(ctype, vis, initial_state, name, cfg)
+
+
+def _default_collection_id(project_id: str, default_id: str) -> str:
+    """The id of a project's default collection. The deployment's primary
+    project (== `default_id`, the §22.13 resolved default) gets the stable
+    literal `'default'` — matching migration 029's seed so the upsert *merges*
+    onto the migration-seeded row rather than duplicating it (critical on a
+    fresh deploy where the bootstrap `default` project is later restamped to the
+    configured id). Any additional project keys its default collection by its own
+    id, keeping the collection PK globally unique (pre-S5 multi-project)."""
+    return "default" if project_id == default_id else project_id
+
+
+def apply_registry(doc: RegistryDoc, registry_sha: str, default_id: str) -> None:
+    """Upsert the parsed registry into projects + their default collections +
+    the deployment singleton. Idempotent.
+
+    §22 three-tier (S1): a project carries the grouping-tier fields (name,
+    content_repo, visibility, config); the per-corpus fields (`type`,
+    `initial_state`) live on the project's default collection. §22.4a: `type` is
+    immutable — a change against an existing collection is rejected (skip the
+    type change + log), never applied. Projects absent from the registry are
+    left in place (archival is out of scope for M3; they stop refreshing).
+    """
+    with db.tx() as conn:
+        for e in doc.projects:
+            cid = _default_collection_id(e.id, default_id)
+            existing = conn.execute(
+                "SELECT type FROM collections WHERE id = ?", (cid,)
+            ).fetchone()
+            type_locked = existing is not None and existing["type"] != e.type
+            if type_locked:
+                log.error(
+                    "registry: refusing immutable type change on collection %s (%s -> %s)",
+                    cid, existing["type"], e.type,
+                )
+            # The project (grouping tier) always refreshes.
+            conn.execute(
+                """
+                INSERT INTO projects
+                    (id, name, content_repo, visibility, config_json, registry_sha, updated_at)
+                VALUES (?, ?, ?, ?, ?, ?, datetime('now'))
+                ON CONFLICT(id) DO UPDATE SET
+                    name = excluded.name,
+                    content_repo = excluded.content_repo,
+                    visibility = excluded.visibility,
+                    config_json = excluded.config_json,
+                    registry_sha = excluded.registry_sha,
+                    updated_at = datetime('now')
+                """,
+                (e.id, e.name, e.content_repo, e.visibility, json.dumps(e.config), registry_sha),
+            )
+            # The default collection (corpus tier). On an immutable-type
+            # conflict, keep the stored type but still refresh the rest.
+            effective_type = existing["type"] if type_locked else e.type
+            conn.execute(
+                """
+                INSERT INTO collections
+                    (id, project_id, type, subfolder, initial_state, visibility, name, registry_sha, updated_at)
+                VALUES (?, ?, ?, '', ?, ?, ?, ?, datetime('now'))
+                ON CONFLICT(id) DO UPDATE SET
+                    project_id = excluded.project_id,
+                    type = excluded.type,
+                    initial_state = excluded.initial_state,
+                    visibility = excluded.visibility,
+                    name = excluded.name,
+                    registry_sha = excluded.registry_sha,
+                    updated_at = datetime('now')
+                """,
+                (cid, e.id, effective_type, e.initial_state, e.visibility, e.name, registry_sha),
+            )
+        conn.execute(
+            """
+            UPDATE deployment
+               SET name = ?, tagline = ?, registry_sha = ?, updated_at = datetime('now')
+             WHERE id = 1
+            """,
+            (doc.deployment_name, doc.deployment_tagline, registry_sha),
+        )
+
+
+def _strictest_visibility(a: str, b: str) -> str:
+    """The stricter of two §22.5 visibilities on the public-exposure axis
+    (`public` < `unlisted` < `gated`). Used to enforce that a collection is set
+    only as strict or stricter than its project (S3 operator decision)."""
+    rank = {"public": 0, "unlisted": 1, "gated": 2}
+    return a if rank.get(a, 2) >= rank.get(b, 2) else b
+
+
+def _upsert_named_collection(
+    proj: ProjectEntry, subdir: str, ce: CollectionEntry, sha: str
+) -> None:
+    """Upsert one named collection (S2). Type is immutable (§22.4a): a type
+    change against an existing row is refused (logged, not applied). A None
+    manifest visibility inherits the project's visibility; a manifest that tries
+    to be *looser* than its project is clamped to the project's (S3 strictness:
+    a collection may narrow but never widen its project's visibility)."""
+    requested = ce.visibility or proj.visibility
+    visibility = _strictest_visibility(requested, proj.visibility)
+    if visibility != requested:
+        log.warning(
+            "registry: collection %s visibility %r looser than project %s %r — "
+            "clamped to %r (S3 strictness)",
+            subdir, requested, proj.id, proj.visibility, visibility,
+        )
+    with db.tx() as conn:
+        existing = conn.execute(
+            "SELECT type FROM collections WHERE id = ?", (subdir,)
+        ).fetchone()
+        if existing is not None and existing["type"] != ce.type:
+            log.error(
+                "registry: refusing immutable type change on collection %s (%s -> %s)",
+                subdir, existing["type"], ce.type,
+            )
+            return
+        conn.execute(
+            """
+            INSERT INTO collections
+                (id, project_id, type, subfolder, initial_state, visibility, name, config_json, registry_sha, updated_at)
+            VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, datetime('now'))
+            ON CONFLICT(id) DO UPDATE SET
+                project_id = excluded.project_id,
+                initial_state = excluded.initial_state,
+                visibility = excluded.visibility,
+                name = excluded.name,
+                config_json = excluded.config_json,
+                registry_sha = excluded.registry_sha,
+                updated_at = datetime('now')
+            """,
+            (subdir, proj.id, ce.type, subdir, ce.initial_state, visibility, ce.name,
+             json.dumps(ce.config), sha),
+        )
+
+
+async def _mirror_named_collections(config: Config, gitea: Gitea, doc: RegistryDoc, sha: str) -> None:
+    """§22 S2: named collections are declared by `.collection.yaml` manifests
+    inside each project's content repo (the default collection comes from
+    projects.yaml). Walk each content repo root; a subdir carrying a manifest
+    becomes a collection keyed by the subdir name. Tolerant: a transport or
+    parse failure on one project/collection logs and is skipped, never aborts
+    the wider mirror (keep last-good)."""
+    for proj in doc.projects:
+        try:
+            items = await gitea.list_dir(config.gitea_org, proj.content_repo, "", ref="main")
+        except Exception as e:  # noqa: BLE001 — GiteaError/transport: tolerate
+            log.warning("registry: cannot list %s root: %s", proj.content_repo, e)
+            continue
+        for it in items:
+            if it.get("type") != "dir":
+                continue
+            subdir = it["name"]
+            manifest = await gitea.get_contents(
+                config.gitea_org, proj.content_repo, f"{subdir}/.collection.yaml", ref="main"
+            )
+            if not manifest or manifest.get("type") != "file":
+                continue
+            mtext = base64.b64decode(manifest["content"]).decode("utf-8")
+            try:
+                ce = parse_collection_manifest(mtext)
+            except RegistryError as e:
+                log.error("registry: bad manifest %s/%s: %s", proj.content_repo, subdir, e)
+                continue
+            _upsert_named_collection(proj, subdir, ce, sha)
+
+
+async def refresh_registry(config: Config, gitea: Gitea) -> None:
+    """Mirror REGISTRY_REPO/projects.yaml into projects + deployment.
+
+    Idempotent. Raises RegistryError on a missing/invalid file and GiteaError
+    on transport failure; the caller chooses fatal-vs-tolerated.
+    """
+    item = await gitea.get_contents(
+        config.gitea_org, config.registry_repo, "projects.yaml", ref="main"
+    )
+    if not item or item.get("type") != "file":
+        raise RegistryError(
+            f"{config.gitea_org}/{config.registry_repo}/projects.yaml not found"
+        )
+    text = base64.b64decode(item["content"]).decode("utf-8")
+    # Prefer the file's last commit sha for provenance (production Gitea
+    # includes it on the contents response); fall back to the blob sha.
+    sha = item.get("last_commit_sha") or item.get("sha") or ""
+    doc = parse_registry(text)
+    from . import projects as projects_mod
+    apply_registry(doc, sha, projects_mod.resolved_default_id(config))
+    # §22 S2: discover + upsert named collections from each content repo.
+    await _mirror_named_collections(config, gitea, doc, sha)
+    log.info("registry: mirrored %d project(s) at %s", len(doc.projects), sha)

backend/app/rfc_links.py

@@ -1,43 +1,95 @@
-"""Roadmap #28 Part 1 — auto-link RFC references in submitted prose.
+"""Roadmap #28 — scan submitted prose for RFC-shaped references.
 
-Scans plain-text PR descriptions and comment bodies for references to
-existing **accepted** (state='active') RFCs and returns a structured list
+The scanner splits a plain-text PR description / comment body into a list
 of *segments* the frontend renders: plain-text runs interleaved with
-``{"type": "rfc", ...}`` link segments. The backend never emits HTML —
-the frontend maps link segments onto React anchors — so the surface is
-XSS-safe by construction and independent of any HTML-sanitization layer.
+typed link segments. The backend never emits HTML — the frontend maps
+each segment onto a React node — so the surface is XSS-safe by
+construction and independent of any HTML-sanitization layer.
 
-**Read-time enrichment, not submit-time persistence.** The roadmap row
-phrases the scan as happening "at submit/post time"; this module instead
-enriches on read. The intent the roadmap actually names — "not as live
-compose preview" — is honored (drafts are never scanned, only submitted
-content on the read paths). Read-time was chosen for three reasons:
+Three buckets, one scan (Parts 1–3):
 
-  1. Correctness — links track the *live* active-RFC set. A newly-accepted
-     RFC starts linking in older comments; a withdrawn RFC stops linking
-     everywhere. Submit-time freezing would drift stale.
-  2. Zero migration — no derived data to store. (A concurrent session
-     already holds migration 023; staying migration-free keeps this slice
-     conflict-free as well as simpler.)
-  3. Cost — the active-RFC corpus is small and cache-resident, so building
-     the term index and scanning a ≤20k-char body per read is cheap.
+  * ``{"type": "rfc", ...}``          — Part 1. The term matches an
+    **accepted** (``state='active'``) RFC; renders as a link to it.
+  * ``{"type": "rfc-pending", ...}``  — Part 3. The term matches a
+    **pending** RFC — a super-draft (``state='super-draft'``: accepted
+    as an idea but not yet graduated to an active RFC) — which has an
+    owner and a contribution surface. Renders as an "ask to contribute"
+    affordance carrying the owner's display name.
+  * ``{"type": "rfc-candidate", ...}`` — Part 2. The term is a
+    strong-candidate that does **not** yet have a defining RFC. Renders
+    (for a viewer with create rights) as a "create RFC for '<term>'"
+    affordance that pre-fills the propose flow.
 
-**Matching is conservative by design.** Only references that are unlikely
-to be coincidental link:
+Precedence at any position is active > pending > candidate, then
+longest-match-first — an active link always wins over a contribute offer
+which always wins over a create offer for the same span.
+
+**Read-time enrichment, not submit-time persistence** (unchanged from
+Part 1): drafts are never scanned, only submitted content on the read
+paths, so links/offers track the *live* corpus. The active-RFC corpus,
+super-draft corpus, and tag taxonomy are all small and cache-resident,
+so building the index and scanning a ≤20k-char body per read is cheap.
+
+**Matching stays conservative by design.** A reference links/offers only
+when it is unlikely to be coincidental:
 
   * ``rfc_id`` tokens (e.g. ``RFC-0001``) — inherently specific.
   * Multi-word titles (containing whitespace, e.g. ``Open Human Model``).
   * Hyphenated slugs (containing ``-``, e.g. ``open-human-model``).
 
-Single common-word titles or slugs (e.g. a hypothetical RFC titled
-"Human") are deliberately NOT auto-linked — they would turn every prose
-"human" into a link. Surfacing those is the job of the roadmap's
-"curated canonical-terms list", an explicit per-deployment opt-in left as
-a future extension rather than guessed at here.
+Single common-word titles/slugs are deliberately NOT matched — they
+would turn every prose occurrence into an affordance.
+
+**Part 2 candidate heuristic.** A candidate term is a **multi-word tag**
+from the #27 tag taxonomy (the de-facto set of tags the corpus already
+carries) that has no defining RFC (no active or super-draft RFC whose
+slug or title is that term). Multi-word is the same false-positive guard
+the title rule uses: a single common tag word (``identity``) would be
+far too noisy. Broader candidate detection — capitalized multi-word
+phrases mined from the text, terms repeated across recently-touched PRs,
+or the #27 Haiku (``ANTHROPIC_API_KEY``) pathway — is a sanctioned but
+deferred extension; the conservative tag-taxonomy heuristic is chosen
+here to match Part 1's false-positive-averse philosophy.
 """
 from __future__ import annotations
 
-from typing import Any, Iterable
+import json
+import re
+from typing import Any, Iterable, NamedTuple
+
+
+class Term(NamedTuple):
+    """One match key plus what to emit when it hits.
+
+    ``key`` is the lowercase span to match (word-boundary, longest-first).
+    ``kind`` is ``'active' | 'pending' | 'candidate'`` and selects the
+    emitted segment shape. ``slug``/``title`` carry the target RFC (active
+    + pending); ``owner`` is the pending RFC's owner display name;
+    ``term`` is the candidate's canonical display spelling.
+    """
+
+    key: str
+    kind: str = "active"
+    slug: str = ""
+    title: str = ""
+    owner: str = ""
+    term: str = ""
+
+
+# Lower number = higher precedence when two keys of equal length match at
+# the same position. A real link beats a contribute offer beats a create
+# offer.
+_KIND_PRIORITY = {"active": 0, "pending": 1, "candidate": 2}
+
+
+def _coerce(t: Term | tuple) -> Term:
+    """Accept the legacy ``(key, slug, title)`` 3-tuple (treated as an
+    active term) alongside :class:`Term`, so direct unit-test callers and
+    older call sites keep working."""
+    if isinstance(t, Term):
+        return t
+    key, slug, title = t  # legacy active 3-tuple
+    return Term(key=key, kind="active", slug=slug, title=title)
 
 
 def _is_word_char(c: str) -> bool:
@@ -46,18 +98,37 @@ def _is_word_char(c: str) -> bool:
     return c.isalnum() or c in ("-", "_")
 
 
-def segment_text(text: str | None, terms: list[tuple[str, str, str]]) -> list[dict[str, Any]]:
-    """Split ``text`` into text / rfc-link segments against ``terms``.
+def _emit(term: Term, label: str) -> dict[str, Any]:
+    """The segment dict for a matched ``term``; ``label`` preserves source
+    casing."""
+    if term.kind == "pending":
+        return {
+            "type": "rfc-pending",
+            "slug": term.slug,
+            "label": label,
+            "title": term.title,
+            "owner": term.owner,
+        }
+    if term.kind == "candidate":
+        return {"type": "rfc-candidate", "label": label, "term": term.term}
+    return {"type": "rfc", "slug": term.slug, "label": label, "title": term.title}
 
-    ``terms`` is a list of ``(key_lower, slug, title)`` tuples; callers
-    pass it pre-sorted longest-first so the longest match wins at any
-    position (so "Open Human Model" wins over a bare "Open"). Matching is
-    case-insensitive and respects word boundaries on both ends. The
-    returned ``label`` preserves the source casing.
+
+def segment_text(text: str | None, terms: Iterable[Term | tuple]) -> list[dict[str, Any]]:
+    """Split ``text`` into text / link segments against ``terms``.
+
+    ``terms`` are :class:`Term` objects (or legacy ``(key, slug, title)``
+    active 3-tuples). Matching is case-insensitive, respects word
+    boundaries on both ends, and prefers the longest key — then higher
+    :data:`_KIND_PRIORITY` — at any position.
 
     Always returns at least one segment; for empty/None input that is a
     single empty text segment, so callers can render uniformly.
     """
+    ordered = sorted(
+        (_coerce(t) for t in terms),
+        key=lambda t: (-len(t.key), _KIND_PRIORITY.get(t.kind, 9)),
+    )
     if not text:
         return [{"type": "text", "text": text or ""}]
 
@@ -67,28 +138,23 @@ def segment_text(text: str | None, terms: list[tuple[str, str, str]]) -> list[di
     n = len(text)
     i = 0
     while i < n:
-        match: tuple[str, str, str, int] | None = None
-        for key, slug, title in terms:
-            klen = len(key)
-            if klen == 0 or not low.startswith(key, i):
+        match: tuple[Term, int] | None = None
+        for term in ordered:
+            klen = len(term.key)
+            if klen == 0 or not low.startswith(term.key, i):
                 continue
             before = text[i - 1] if i > 0 else ""
             after = text[i + klen] if i + klen < n else ""
             if _is_word_char(before) or _is_word_char(after):
                 continue
-            match = (key, slug, title, klen)
+            match = (term, klen)
             break
         if match is not None:
-            _key, slug, title, klen = match
+            term, klen = match
             if buf:
                 out.append({"type": "text", "text": "".join(buf)})
                 buf = []
-            out.append({
-                "type": "rfc",
-                "slug": slug,
-                "label": text[i:i + klen],
-                "title": title,
-            })
+            out.append(_emit(term, text[i:i + klen]))
             i += klen
         else:
             buf.append(text[i])
@@ -99,8 +165,8 @@ def segment_text(text: str | None, terms: list[tuple[str, str, str]]) -> list[di
 
 
 def _keys_for(slug: str, title: str, rfc_id: str | None) -> Iterable[str]:
-    """The match keys an active RFC contributes. See the module docstring
-    for why each gate exists (conservative, false-positive-averse)."""
+    """The match keys an RFC contributes. See the module docstring for why
+    each gate exists (conservative, false-positive-averse)."""
     if rfc_id:
         rid = rfc_id.strip()
         if len(rid) >= 2:
@@ -117,13 +183,23 @@ def _keys_for(slug: str, title: str, rfc_id: str | None) -> Iterable[str]:
             yield s.lower()
 
 
+def _slugify(term: str) -> str:
+    """Deterministic kebab-case — mirrors the propose modal's slugify so a
+    tag's would-be slug compares correctly against existing RFC slugs."""
+    return re.sub(r"-+$", "", re.sub(r"^-+", "", re.sub(r"[^a-z0-9]+", "-", term.lower().strip())))
+
+
 class LinkIndex:
     """A reusable term index built once per request and applied to many
     bodies (a PR's description plus every comment on it)."""
 
-    def __init__(self, terms: list[tuple[str, str, str]]):
-        # Longest key first so the longest reference wins at each position.
-        self._terms = sorted(terms, key=lambda t: len(t[0]), reverse=True)
+    def __init__(self, terms: Iterable[Term | tuple]):
+        # Coerce + order once; segment_text re-sorts defensively but a
+        # pre-sorted list keeps the per-body cost to the scan itself.
+        self._terms: list[Term] = sorted(
+            (_coerce(t) for t in terms),
+            key=lambda t: (-len(t.key), _KIND_PRIORITY.get(t.kind, 9)),
+        )
 
     def __bool__(self) -> bool:
         return bool(self._terms)
@@ -132,27 +208,126 @@ class LinkIndex:
         return segment_text(text, self._terms)
 
 
-def build_index(conn, *, exclude_slug: str | None = None) -> LinkIndex:
-    """Build a :class:`LinkIndex` from the accepted (active) RFC corpus.
+def _owner_display(conn, owners_json: str | None, proposed_by: str | None) -> str:
+    """The display name to show for a pending RFC's owner. First entry of
+    ``owners_json`` resolved to its user row's display name, falling back
+    to the bare login, then ``proposed_by``, then a neutral noun."""
+    login = None
+    try:
+        owners = json.loads(owners_json or "[]")
+        if isinstance(owners, list):
+            login = next((o for o in owners if isinstance(o, str) and o.strip()), None)
+    except (ValueError, TypeError):
+        login = None
+    if login:
+        row = conn.execute(
+            "SELECT display_name FROM users WHERE gitea_login = ?", (login,)
+        ).fetchone()
+        if row and row["display_name"]:
+            return row["display_name"]
+        return login
+    return (proposed_by or "").strip() or "the proposer"
 
-    ``exclude_slug`` drops the RFC the surrounding surface is itself scoped
-    to, so an RFC's own title/id/slug don't self-link inside its own PR or
-    discussion. ``ORDER BY slug`` makes key de-duplication deterministic
-    when two RFCs would contribute the same key (first slug wins)."""
-    rows = conn.execute(
-        "SELECT slug, title, rfc_id FROM cached_rfcs WHERE state = 'active' ORDER BY slug"
-    ).fetchall()
-    terms: list[tuple[str, str, str]] = []
+
+def _tag_universe(conn) -> list[str]:
+    """Distinct tags across the cached corpus (the #27 de-facto taxonomy),
+    preserving original spelling; case-deduped."""
+    rows = conn.execute("SELECT tags_json FROM cached_rfcs").fetchall()
+    out: list[str] = []
     seen: set[str] = set()
     for r in rows:
+        try:
+            tags = json.loads(r["tags_json"] or "[]")
+        except (ValueError, TypeError):
+            continue
+        if not isinstance(tags, list):
+            continue
+        for t in tags:
+            if not isinstance(t, str):
+                continue
+            tag = t.strip()
+            low = tag.lower()
+            if tag and low not in seen:
+                seen.add(low)
+                out.append(tag)
+    return out
+
+
+def build_index(
+    conn,
+    *,
+    exclude_slug: str | None = None,
+    include_pending: bool = True,
+    include_candidates: bool = True,
+) -> LinkIndex:
+    """Build a :class:`LinkIndex` over the three buckets.
+
+    ``exclude_slug`` drops the RFC the surrounding surface is itself scoped
+    to, so an RFC's own title/id/slug don't self-link (or self-offer)
+    inside its own PR or discussion. Precedence is enforced by insertion
+    order — active keys are added first and a later bucket never overrides
+    an already-claimed key.
+    """
+    terms: list[Term] = []
+    seen: set[str] = set()
+
+    def add(key: str, term: Term) -> None:
+        if key in seen:
+            return
+        seen.add(key)
+        terms.append(term)
+
+    # --- Part 1: accepted (active) RFCs. ORDER BY slug makes key
+    # de-duplication deterministic when two RFCs would contribute the
+    # same key (first slug wins). ---
+    active_rows = conn.execute(
+        "SELECT slug, title, rfc_id FROM cached_rfcs WHERE state = 'active' ORDER BY slug"
+    ).fetchall()
+    # Track every slug + title that *has* a defining RFC, so Part 2 never
+    # offers to create one that already exists (active or pending).
+    defined_slugs: set[str] = set()
+    defined_titles: set[str] = set()
+    for r in active_rows:
         slug = r["slug"]
+        defined_slugs.add((slug or "").lower())
+        defined_titles.add((r["title"] or "").strip().lower())
         if exclude_slug is not None and slug == exclude_slug:
             continue
         title = r["title"] or ""
         rfc_id = r["rfc_id"] if "rfc_id" in r.keys() else None
         for key in _keys_for(slug, title, rfc_id):
-            if key in seen:
+            add(key, Term(key=key, kind="active", slug=slug, title=title))
+
+    # --- Part 3: pending (super-draft) RFCs. ---
+    pending_rows = conn.execute(
+        """
+        SELECT slug, title, rfc_id, owners_json, proposed_by
+          FROM cached_rfcs WHERE state = 'super-draft' ORDER BY slug
+        """
+    ).fetchall()
+    for r in pending_rows:
+        slug = r["slug"]
+        defined_slugs.add((slug or "").lower())
+        defined_titles.add((r["title"] or "").strip().lower())
+        if not include_pending:
+            continue
+        if exclude_slug is not None and slug == exclude_slug:
+            continue
+        title = r["title"] or ""
+        rfc_id = r["rfc_id"] if "rfc_id" in r.keys() else None
+        owner = _owner_display(conn, r["owners_json"], r["proposed_by"])
+        for key in _keys_for(slug, title, rfc_id):
+            add(key, Term(key=key, kind="pending", slug=slug, title=title, owner=owner))
+
+    # --- Part 2: strong-candidate terms with no defining RFC. ---
+    if include_candidates:
+        for tag in _tag_universe(conn):
+            low = tag.lower()
+            # Conservative: multi-word tags only (same guard as titles).
+            if " " not in tag and "\t" not in tag:
                 continue
-            seen.add(key)
-            terms.append((key, slug, title))
+            if low in defined_titles or low in defined_slugs or _slugify(tag) in defined_slugs:
+                continue
+            add(low, Term(key=low, kind="candidate", term=tag))
+
     return LinkIndex(terms)

backend/app/turnstile.py

@@ -73,6 +73,19 @@ def _siteverify_url() -> str:
     return os.environ.get("TURNSTILE_SITEVERIFY_URL", "").strip() or SITEVERIFY_URL
 
 
+async def _siteverify_post(url: str, data: dict) -> httpx.Response:
+    """Perform the siteverify POST on an `httpx.AsyncClient`.
+
+    Isolated as a narrow seam (I4, security-audit-0026): the call is
+    awaited so a slow CloudFlare response can't block the event loop,
+    and tests patch *this function* rather than the shared
+    `httpx.AsyncClient` (which other modules — gitea, docs — also
+    construct, so a global patch would break app boot).
+    """
+    async with httpx.AsyncClient(timeout=10.0) as client:
+        return await client.post(url, data=data)
+
+
 @dataclass
 class VerifyOutcome:
     """Result of a Turnstile siteverify call.
@@ -98,7 +111,7 @@ class VerifyOutcome:
     reason: str
 
 
-def verify_token(token: str | None, *, client_ip: str | None = None) -> VerifyOutcome:
+async def verify_token(token: str | None, *, client_ip: str | None = None) -> VerifyOutcome:
     """Validate a Turnstile token against CloudFlare's siteverify endpoint.
 
     Returns a VerifyOutcome describing whether the calling endpoint
@@ -108,9 +121,14 @@ def verify_token(token: str | None, *, client_ip: str | None = None) -> VerifyOu
       * 'misconfigured' → 500 "auth misconfigured"
       * 'missing-token' / 'failed' / 'network' → 400 "verification failed"
 
-    Tests monkeypatch `httpx.post` (or set `TURNSTILE_SITEVERIFY_URL`
-    + a MockTransport client) to avoid touching the real CloudFlare
-    endpoint. No real keys are ever embedded in tests.
+    Async (I4, security-audit-0026): the siteverify call is awaited on an
+    `httpx.AsyncClient` so a slow CloudFlare response can't block the
+    event loop (the prior synchronous `httpx.post` stalled the single
+    worker for up to the 10s timeout). Callers must `await` it.
+
+    Tests monkeypatch `_siteverify_post` (the narrow async seam) to avoid
+    touching the real CloudFlare endpoint and to keep the patch off the
+    shared `httpx.AsyncClient`. No real keys are ever embedded in tests.
     """
     secret = _secret()
     required = _required()
@@ -133,7 +151,7 @@ def verify_token(token: str | None, *, client_ip: str | None = None) -> VerifyOu
         data["remoteip"] = client_ip
 
     try:
-        response = httpx.post(_siteverify_url(), data=data, timeout=10.0)
+        response = await _siteverify_post(_siteverify_url(), data)
         payload = response.json()
     except Exception as exc:  # network, JSON parse, etc.
         log.warning("Turnstile siteverify call failed: %s", exc)

backend/app/webhooks.py

@@ -16,7 +16,7 @@ import os
 
 from fastapi import APIRouter, Header, HTTPException, Request
 
-from . import cache, db
+from . import cache, db, projects as projects_mod, registry as registry_mod
 from .config import Config
 from .gitea import Gitea
 
@@ -79,9 +79,22 @@ def make_router(config: Config, gitea: Gitea) -> APIRouter:
         except Exception:
             payload = {}
         repo_full = (payload.get("repository") or {}).get("full_name") or ""
-        meta_full = f"{config.gitea_org}/{config.meta_repo}"
+        registry_full = f"{config.gitea_org}/{config.registry_repo}"
+        content_repo = projects_mod.default_content_repo(config)
+        if not content_repo:
+            log.warning("webhook: default project content_repo is unknown; corpus refresh skipped")
+        content_full = f"{config.gitea_org}/{content_repo}" if content_repo else None
         try:
-            if repo_full == meta_full or not repo_full:
+            if repo_full == registry_full:
+                # §22.2: a registry-repo push re-mirrors the projects table.
+                # Tolerate a malformed projects.yaml (keep last-good rows); let a
+                # transport error bubble to the outer 500 so an unreachable Gitea
+                # on a registry push is loud rather than silently dropped.
+                try:
+                    await registry_mod.refresh_registry(config, gitea)
+                except registry_mod.RegistryError:
+                    log.exception("registry webhook: invalid projects.yaml; keeping last-good")
+            elif content_full and (repo_full == content_full or not repo_full):
                 await cache.refresh_meta_repo(config, gitea)
                 await cache.refresh_meta_branches(config, gitea)
                 await cache.refresh_meta_pulls(config, gitea)
@@ -90,11 +103,6 @@ def make_router(config: Config, gitea: Gitea) -> APIRouter:
                 if slug:
                     await cache.refresh_rfc_repo(config, gitea, slug)
                 else:
-                    # v0.18.0: the proposal's "unknown-repo logging"
-                    # gesture — a hook on a fork or a stale repo binding
-                    # used to silently 200-OK here, hiding the
-                    # misconfiguration. Now the operator sees it in
-                    # the log.
                     log.info(
                         "webhook received for unknown repo: repo_full=%s event=%s "
                         "(no cached_rfcs row matched; hook may be on a fork or stale)",

backend/migrations/023_otc_verify_lockout.sql

@@ -0,0 +1,18 @@
+-- v0.25.0 / security audit 0026, finding H1.
+--
+-- The OTC verify path had no attempt-limit or lockout, unlike the
+-- passcode path (015_passcode.sql gave users.passcode_failed_attempts +
+-- passcode_locked_until). This table gives the OTC verify endpoint the
+-- same per-identity lockout shape. It is keyed by email rather than
+-- user_id because an OTC sign-in may not have a users row yet — the row
+-- is provisioned only on a *successful* verify, so the lockout state has
+-- to survive independently of it.
+--
+-- The per-IP rate limiter (app/ratelimit.py) is the primary brute-force
+-- defense; this table is the parity layer that mirrors the passcode
+-- lockout and persists across restarts.
+CREATE TABLE IF NOT EXISTS otc_verify_state (
+    email TEXT PRIMARY KEY,
+    failed_attempts INTEGER NOT NULL DEFAULT 0,
+    locked_until TEXT
+);

backend/migrations/024_contribution_requests.sql

@@ -0,0 +1,59 @@
+-- v0.29.0 / roadmap #28 Part 3 — offer-to-contribute-to-a-pending-RFC.
+--
+-- When the #28 scanner matches a term in submitted PR/comment text to a
+-- *pending* RFC (a super-draft: accepted-as-an-idea but not yet graduated
+-- to an active RFC), the reader is offered a "ask to contribute" popover.
+-- Submitting it lands a row here AND a notification in each owner's §15
+-- inbox; the owner can accept (which fires #12's owner-invite flow with
+-- the requester as the invitee) or decline (the requester is notified and
+-- the request closes).
+--
+-- A "pending RFC" is scoped to a super-draft (cached_rfcs.state =
+-- 'super-draft'): it is in cached_rfcs (so the rfc_invitations FK that the
+-- accept path reuses resolves), it carries owners (owners_json) to route
+-- the request to, and it already has a discussion/contribution surface to
+-- open. Pre-merge idea PRs (not yet in cached_rfcs, no contribution
+-- surface) are deliberately out of scope — see backend/app/rfc_links.py.
+--
+-- The request row is the persistent record; the inbox notification is the
+-- owner-facing actionable surface keyed back to it via `notification_id`.
+
+CREATE TABLE IF NOT EXISTS contribution_requests (
+    id                  INTEGER PRIMARY KEY AUTOINCREMENT,
+    rfc_slug            TEXT NOT NULL
+                            REFERENCES cached_rfcs(slug) ON DELETE CASCADE,
+    requester_user_id   INTEGER NOT NULL
+                            REFERENCES users(id) ON DELETE CASCADE,
+    -- The term in the PR/comment text that surfaced the offer (e.g. the
+    -- super-draft's title). Carried for the owner's context line and the
+    -- requester's "what RFC" anchor; not a foreign key.
+    matched_term        TEXT NOT NULL,
+    -- The three contribute-request fields (§15 / #26 vocabulary).
+    -- `who_i_am` and `why` are required; `use_case` mirrors #26's
+    -- optional ground-truth field.
+    who_i_am            TEXT NOT NULL,
+    why                 TEXT NOT NULL,
+    use_case            TEXT,
+    status              TEXT NOT NULL DEFAULT 'pending'
+                            CHECK (status IN ('pending', 'accepted', 'declined')),
+    created_at          TEXT NOT NULL DEFAULT (datetime('now')),
+    decided_at          TEXT,
+    decided_by_user_id  INTEGER REFERENCES users(id) ON DELETE SET NULL,
+    -- The rfc_invitations row minted on accept (the #12 reuse), and the
+    -- owner-facing notification row that carries the Accept/Decline action.
+    invitation_id       INTEGER REFERENCES rfc_invitations(id) ON DELETE SET NULL,
+    notification_id     INTEGER REFERENCES notifications(id) ON DELETE SET NULL
+);
+
+CREATE INDEX IF NOT EXISTS idx_contribution_requests_rfc
+    ON contribution_requests(rfc_slug, status);
+
+CREATE INDEX IF NOT EXISTS idx_contribution_requests_requester
+    ON contribution_requests(requester_user_id, status);
+
+-- At most one open (pending) request per (RFC, requester): a second ask
+-- while one is still pending is a 409, not a duplicate row. A decided
+-- request (accepted/declined) does not block a fresh ask later.
+CREATE UNIQUE INDEX IF NOT EXISTS idx_contribution_requests_one_open
+    ON contribution_requests(rfc_slug, requester_user_id)
+    WHERE status = 'pending';

backend/migrations/025_retired_state.sql

@@ -0,0 +1,61 @@
+-- §3 / §13.7: add the `retired` soft-delete state to cached_rfcs.
+--
+-- SQLite cannot ALTER a CHECK constraint in place, so we rebuild the table
+-- with the expanded constraint and copy the rows across. cached_rfcs is a
+-- §4 cache (reconstructible from Gitea by the reconciler), and nothing
+-- holds a foreign key into it, so the rebuild is safe; we preserve the
+-- existing rows anyway to avoid a needless full re-read on upgrade.
+--
+-- The rebuilt table must carry EVERY column cached_rfcs has accumulated,
+-- including the ones added by later migrations via ALTER TABLE ADD COLUMN:
+--   009_per_rfc_models  -> models_json
+--   010_funder          -> funder_login
+--   021_proposed_use_case -> proposed_use_case
+-- They are appended last (matching the live column order) and copied
+-- across explicitly so nothing is dropped.
+--
+-- The migration runner wraps this file in a single BEGIN/COMMIT, so the
+-- swap is atomic.
+
+CREATE TABLE cached_rfcs_new (
+    slug                TEXT PRIMARY KEY,
+    title               TEXT NOT NULL,
+    state               TEXT NOT NULL CHECK (state IN ('super-draft', 'active', 'withdrawn', 'retired')),
+    rfc_id              TEXT,                -- 'RFC-NNNN' or NULL (NULL is also valid for an active RFC graduated without a number, §13.2)
+    repo                TEXT,                -- 'org/repo' or NULL; always NULL under the meta-only topology (§1)
+    proposed_by         TEXT,
+    proposed_at         TEXT,
+    graduated_at        TEXT,
+    graduated_by        TEXT,
+    owners_json         TEXT NOT NULL DEFAULT '[]',
+    arbiters_json       TEXT NOT NULL DEFAULT '[]',
+    tags_json           TEXT NOT NULL DEFAULT '[]',
+    body                TEXT,
+    body_sha            TEXT,
+    last_main_commit_at TEXT,
+    last_entry_commit_at TEXT,
+    updated_at          TEXT NOT NULL DEFAULT (datetime('now')),
+    models_json         TEXT,                -- 009_per_rfc_models
+    funder_login        TEXT,                -- 010_funder
+    proposed_use_case   TEXT                 -- 021_proposed_use_case
+);
+
+INSERT INTO cached_rfcs_new
+    (slug, title, state, rfc_id, repo, proposed_by, proposed_at,
+     graduated_at, graduated_by, owners_json, arbiters_json, tags_json,
+     body, body_sha, last_main_commit_at, last_entry_commit_at, updated_at,
+     models_json, funder_login, proposed_use_case)
+SELECT
+     slug, title, state, rfc_id, repo, proposed_by, proposed_at,
+     graduated_at, graduated_by, owners_json, arbiters_json, tags_json,
+     body, body_sha, last_main_commit_at, last_entry_commit_at, updated_at,
+     models_json, funder_login, proposed_use_case
+  FROM cached_rfcs;
+
+DROP TABLE cached_rfcs;
+ALTER TABLE cached_rfcs_new RENAME TO cached_rfcs;
+
+CREATE INDEX idx_cached_rfcs_state ON cached_rfcs (state);
+CREATE INDEX idx_cached_rfcs_last_active ON cached_rfcs (
+    COALESCE(last_main_commit_at, last_entry_commit_at) DESC
+);

backend/migrations/026_projects.sql

@@ -0,0 +1,105 @@
+-- §22 (multi-project deployments) — Slice M1: the project spine.
+--
+-- A deployment now hosts one or more *projects*, each a corpus with its own
+-- content repo, slug/RFC-NNNN namespace, catalog, roster, and branding. The
+-- pre-multi-project single-corpus deployment is the N=1 case: this migration
+-- generates one 'default' project and stamps every existing RFC-scoped row
+-- to it, so the app keeps running exactly as before with the spine
+-- underneath (see docs/design/multi-project-spec.md §22.13).
+--
+-- STRATEGY — additive, no table rebuilds. Every slug-bearing table gets a
+-- `project_id TEXT NOT NULL DEFAULT 'default'` column. The constant default
+-- means every existing INSERT in the codebase that does not yet mention
+-- project_id keeps working and lands rows in the default project; no query
+-- breaks because, with a single project, slugs remain globally unique. The
+-- column carries no inline REFERENCES clause: SQLite's ALTER TABLE ADD
+-- COLUMN forbids a FK column with a non-NULL default. project_id referential
+-- integrity is therefore enforced at the app layer for now; the FK lands
+-- with the table rebuilds below.
+--
+-- ============================================================================
+-- DEFERRED to the slice that activates project #2 (M3/M4). Until a second
+-- project exists these are correct as-is; the moment two projects can share a
+-- slug or a Gitea PR number they become cross-project collision bugs and MUST
+-- be rebuilt (SQLite needs a create-copy-drop-rename per table) to fold
+-- project_id into the key, and to add the project_id FK:
+--   * cached_rfcs            PRIMARY KEY (slug)                  -> (project_id, slug)
+--   * cached_branches        UNIQUE (rfc_slug, branch_name)      -> +project_id
+--   * branch_visibility      UNIQUE (rfc_slug, branch_name)      -> +project_id
+--   * branch_contribute_grants UNIQUE (rfc_slug, branch_name, grantee_user_id) -> +project_id
+--   * stars                  UNIQUE (user_id, rfc_slug)          -> +project_id
+--   * watches                UNIQUE (user_id, rfc_slug)          -> +project_id
+--   * pr_seen                UNIQUE (user_id, rfc_slug, pr_number) -> +project_id
+--   * branch_chat_seen       UNIQUE (user_id, rfc_slug, branch_name) -> +project_id
+--   * funder_consents        PRIMARY KEY (user_id, rfc_slug)      -> +project_id
+--   * rfc_collaborators      UNIQUE INDEX (rfc_slug, user_id)     -> +project_id
+--   * contribution_requests  UNIQUE INDEX (rfc_slug, requester_user_id) WHERE pending -> +project_id
+--   * proposed_use_cases     UNIQUE (scope, pr_number)           -> +project_id
+--                            (PR numbers are per-content-repo = per-project)
+-- cached_prs UNIQUE (repo, pr_number) is already globally unique (repo is the
+-- full 'org/repo' string, distinct per project) and needs no rebuild.
+-- ============================================================================
+
+-- The project registry cache (mirrored from the git registry by the M3
+-- reconciler; rows are never written from user actions). content_repo is
+-- NULL until the mirror — or the M1 startup backfill (§22.13 step 1) — sets
+-- it from the deployment's configured repo.
+CREATE TABLE IF NOT EXISTS projects (
+    id            TEXT PRIMARY KEY,
+    name          TEXT NOT NULL,
+    content_repo  TEXT,
+    visibility    TEXT NOT NULL DEFAULT 'gated'
+                      CHECK (visibility IN ('gated', 'public', 'unlisted')),
+    config_json   TEXT,
+    registry_sha  TEXT,
+    created_at    TEXT NOT NULL DEFAULT (datetime('now')),
+    updated_at    TEXT NOT NULL DEFAULT (datetime('now'))
+);
+
+-- The default project. visibility='public' preserves the pre-multi-project
+-- open-by-default posture (§22.5, §22.13). name is a placeholder the startup
+-- backfill / registry overwrites with the deployment's display name.
+INSERT OR IGNORE INTO projects (id, name, visibility)
+    VALUES ('default', 'default', 'public');
+
+-- Per-(user, project) membership and the §22.6 middle-tier role. This is the
+-- new tier between the §6.1 deployment role (users.role, now deployment-scope
+-- only) and the §6.3 per-RFC authority.
+CREATE TABLE IF NOT EXISTS project_members (
+    project_id  TEXT NOT NULL REFERENCES projects(id) ON DELETE CASCADE,
+    user_id     INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    role        TEXT NOT NULL DEFAULT 'project_viewer'
+                    CHECK (role IN ('project_admin', 'project_contributor', 'project_viewer')),
+    granted_by  INTEGER REFERENCES users(id) ON DELETE SET NULL,
+    granted_at  TEXT NOT NULL DEFAULT (datetime('now')),
+    PRIMARY KEY (project_id, user_id)
+);
+
+CREATE INDEX IF NOT EXISTS idx_project_members_user ON project_members(user_id);
+
+-- The project_id spine across every slug-bearing table. Backfills existing
+-- rows to 'default' via the constant column default.
+ALTER TABLE cached_rfcs              ADD COLUMN project_id TEXT NOT NULL DEFAULT 'default';
+ALTER TABLE cached_branches          ADD COLUMN project_id TEXT NOT NULL DEFAULT 'default';
+ALTER TABLE cached_prs               ADD COLUMN project_id TEXT NOT NULL DEFAULT 'default';
+ALTER TABLE branch_visibility        ADD COLUMN project_id TEXT NOT NULL DEFAULT 'default';
+ALTER TABLE branch_contribute_grants ADD COLUMN project_id TEXT NOT NULL DEFAULT 'default';
+ALTER TABLE stars                    ADD COLUMN project_id TEXT NOT NULL DEFAULT 'default';
+ALTER TABLE threads                  ADD COLUMN project_id TEXT NOT NULL DEFAULT 'default';
+ALTER TABLE changes                  ADD COLUMN project_id TEXT NOT NULL DEFAULT 'default';
+ALTER TABLE pr_seen                  ADD COLUMN project_id TEXT NOT NULL DEFAULT 'default';
+ALTER TABLE branch_chat_seen         ADD COLUMN project_id TEXT NOT NULL DEFAULT 'default';
+ALTER TABLE watches                  ADD COLUMN project_id TEXT NOT NULL DEFAULT 'default';
+ALTER TABLE notifications            ADD COLUMN project_id TEXT NOT NULL DEFAULT 'default';
+ALTER TABLE actions                  ADD COLUMN project_id TEXT NOT NULL DEFAULT 'default';
+ALTER TABLE pr_resolution_branches   ADD COLUMN project_id TEXT NOT NULL DEFAULT 'default';
+ALTER TABLE funder_consents          ADD COLUMN project_id TEXT NOT NULL DEFAULT 'default';
+ALTER TABLE rfc_invitations          ADD COLUMN project_id TEXT NOT NULL DEFAULT 'default';
+ALTER TABLE rfc_collaborators        ADD COLUMN project_id TEXT NOT NULL DEFAULT 'default';
+ALTER TABLE proposed_use_cases       ADD COLUMN project_id TEXT NOT NULL DEFAULT 'default';
+ALTER TABLE contribution_requests    ADD COLUMN project_id TEXT NOT NULL DEFAULT 'default';
+
+-- The catalog/directory lookup the M3 surfaces will make (RFCs in a project).
+-- The per-table composite-key rebuilds in the DEFERRED block above will add
+-- their own (project_id, …) indexes when they land.
+CREATE INDEX IF NOT EXISTS idx_cached_rfcs_project ON cached_rfcs(project_id);

backend/migrations/027_projects_runtime_config.sql

@@ -0,0 +1,31 @@
+-- §22 M3 (Plan A) — additive registry/runtime-config schema.
+--
+-- This is the additive half of M3's backend. It adds the project `type` and
+-- `initial_state` columns (mirrored from the registry), the deployment
+-- singleton (deployment name/tagline mirrored from the registry), and the
+-- §22.4c review columns on cached_rfcs. NO table rebuilds: the §22.13 PK
+-- rebuilds and the default->slug re-stamp ride a later migration (Plan B),
+-- just before a second project can collide (see migration 026's DEFERRED
+-- block and docs/superpowers/specs/2026-06-03-m3-backend-design.md §1/§6).
+
+ALTER TABLE projects ADD COLUMN type TEXT NOT NULL DEFAULT 'document'
+    CHECK (type IN ('document', 'specification', 'bdd'));
+ALTER TABLE projects ADD COLUMN initial_state TEXT NOT NULL DEFAULT 'super-draft'
+    CHECK (initial_state IN ('super-draft', 'active'));
+
+-- Deployment-level identity (name, tagline) mirrored from the registry's
+-- `deployment:` block. A singleton: the CHECK pins it to one row.
+CREATE TABLE IF NOT EXISTS deployment (
+    id           INTEGER PRIMARY KEY CHECK (id = 1),
+    name         TEXT,
+    tagline      TEXT,
+    registry_sha TEXT,
+    updated_at   TEXT NOT NULL DEFAULT (datetime('now'))
+);
+INSERT OR IGNORE INTO deployment (id) VALUES (1);
+
+-- §22.4c review flag + provenance. unreviewed is git-truth (mirrored from
+-- entry frontmatter); it survives a cache rebuild like `state` does.
+ALTER TABLE cached_rfcs ADD COLUMN unreviewed INTEGER NOT NULL DEFAULT 0;
+ALTER TABLE cached_rfcs ADD COLUMN reviewed_at TEXT;
+ALTER TABLE cached_rfcs ADD COLUMN reviewed_by TEXT;

backend/migrations/028_project_scoped_keys.sql

@@ -0,0 +1,276 @@
+-- migrate:no-foreign-keys
+--
+-- §22.13 / §22.4 — fold project_id into the slug-keyed PRIMARY KEY / UNIQUE
+-- constraints that migration 026 deliberately left global, so a *second*
+-- project can hold an entry with the same slug as the first. M1 (026) added
+-- project_id additively (no rebuild); this is the rebuild that activates
+-- project #2, enumerated in 026's header.
+--
+-- SQLite can't ALTER a PK/UNIQUE in place, so each table is rebuilt by the
+-- official procedure: create `<t>__new` with the new constraint, copy, DROP
+-- the live table, rename `<t>__new` -> `<t>`, recreate its indexes. FK
+-- enforcement is OFF for the whole file (the `migrate:no-foreign-keys` marker
+-- above tells the runner to toggle it and run foreign_key_check after).
+--
+-- DROP-the-live-table (rather than rename-live-to-__old) is deliberate: SQLite
+-- rewrites child FK references when you RENAME a *referenced* table, so we drop
+-- the old cached_rfcs (allowed with FK off) and rename the temp in. cached_rfcs
+-- is rebuilt FIRST so rfc_collaborators / contribution_requests can re-point
+-- their FK at its new composite (project_id, slug) key.
+
+-- ── cached_rfcs: PRIMARY KEY (slug) -> (project_id, slug) ──────────────────
+CREATE TABLE cached_rfcs__new (
+    slug                TEXT NOT NULL,
+    title               TEXT NOT NULL,
+    state               TEXT NOT NULL CHECK (state IN ('super-draft', 'active', 'withdrawn', 'retired')),
+    rfc_id              TEXT,
+    repo                TEXT,
+    proposed_by         TEXT,
+    proposed_at         TEXT,
+    graduated_at        TEXT,
+    graduated_by        TEXT,
+    owners_json         TEXT NOT NULL DEFAULT '[]',
+    arbiters_json       TEXT NOT NULL DEFAULT '[]',
+    tags_json           TEXT NOT NULL DEFAULT '[]',
+    body                TEXT,
+    body_sha            TEXT,
+    last_main_commit_at TEXT,
+    last_entry_commit_at TEXT,
+    updated_at          TEXT NOT NULL DEFAULT (datetime('now')),
+    models_json         TEXT,
+    funder_login        TEXT,
+    proposed_use_case   TEXT,
+    project_id          TEXT NOT NULL DEFAULT 'default',
+    unreviewed          INTEGER NOT NULL DEFAULT 0,
+    reviewed_at         TEXT,
+    reviewed_by         TEXT,
+    PRIMARY KEY (project_id, slug)
+);
+INSERT INTO cached_rfcs__new SELECT * FROM cached_rfcs;
+DROP TABLE cached_rfcs;
+ALTER TABLE cached_rfcs__new RENAME TO cached_rfcs;
+CREATE INDEX idx_cached_rfcs_state ON cached_rfcs (state);
+CREATE INDEX idx_cached_rfcs_last_active ON cached_rfcs (
+    COALESCE(last_main_commit_at, last_entry_commit_at) DESC
+);
+CREATE INDEX idx_cached_rfcs_project ON cached_rfcs(project_id);
+
+-- ── rfc_invitations: FK rfc_slug -> cached_rfcs(slug) becomes composite ────
+-- (no key change of its own, but its single-column FK to cached_rfcs is now a
+-- mismatch against the composite PK, so it must be rebuilt too). Rebuilt after
+-- cached_rfcs (its FK target) and before the two tables that FK rfc_invitations.
+CREATE TABLE rfc_invitations__new (
+    id                      INTEGER PRIMARY KEY AUTOINCREMENT,
+    rfc_slug                TEXT NOT NULL,
+    inviter_user_id         INTEGER REFERENCES users(id) ON DELETE SET NULL,
+    invitee_email           TEXT NOT NULL,
+    role_in_rfc             TEXT NOT NULL CHECK (role_in_rfc IN ('contributor', 'discussant')),
+    status                  TEXT NOT NULL DEFAULT 'pending'
+        CHECK (status IN ('pending', 'accepted', 'revoked', 'expired')),
+    token                   TEXT NOT NULL,
+    expires_at              TEXT NOT NULL,
+    created_at              TEXT NOT NULL DEFAULT (datetime('now')),
+    accepted_at             TEXT,
+    accepted_by_user_id     INTEGER REFERENCES users(id) ON DELETE SET NULL,
+    project_id              TEXT NOT NULL DEFAULT 'default',
+    FOREIGN KEY (project_id, rfc_slug) REFERENCES cached_rfcs(project_id, slug) ON DELETE CASCADE
+);
+INSERT INTO rfc_invitations__new SELECT * FROM rfc_invitations;
+DROP TABLE rfc_invitations;
+ALTER TABLE rfc_invitations__new RENAME TO rfc_invitations;
+CREATE UNIQUE INDEX idx_rfc_invitations_token ON rfc_invitations (token);
+CREATE INDEX idx_rfc_invitations_rfc_status ON rfc_invitations (rfc_slug, status);
+CREATE INDEX idx_rfc_invitations_email_status ON rfc_invitations (invitee_email, status);
+
+-- ── cached_branches: UNIQUE (rfc_slug, branch_name) -> +project_id ─────────
+CREATE TABLE cached_branches__new (
+    id              INTEGER PRIMARY KEY AUTOINCREMENT,
+    rfc_slug        TEXT NOT NULL,
+    branch_name     TEXT NOT NULL,
+    head_sha        TEXT,
+    state           TEXT NOT NULL DEFAULT 'open' CHECK (state IN ('open', 'closed', 'deleted')),
+    pinned          INTEGER NOT NULL DEFAULT 0,
+    created_at      TEXT NOT NULL DEFAULT (datetime('now')),
+    last_commit_at  TEXT,
+    closed_at       TEXT,
+    project_id      TEXT NOT NULL DEFAULT 'default',
+    UNIQUE (project_id, rfc_slug, branch_name)
+);
+INSERT INTO cached_branches__new SELECT * FROM cached_branches;
+DROP TABLE cached_branches;
+ALTER TABLE cached_branches__new RENAME TO cached_branches;
+CREATE INDEX idx_cached_branches_rfc ON cached_branches (rfc_slug, state);
+
+-- ── branch_visibility: UNIQUE (rfc_slug, branch_name) -> +project_id ───────
+CREATE TABLE branch_visibility__new (
+    id              INTEGER PRIMARY KEY AUTOINCREMENT,
+    rfc_slug        TEXT NOT NULL,
+    branch_name     TEXT NOT NULL,
+    read_public     INTEGER NOT NULL DEFAULT 1,
+    contribute_mode TEXT NOT NULL DEFAULT 'just-me' CHECK (contribute_mode IN ('just-me', 'specific', 'any-contributor')),
+    project_id      TEXT NOT NULL DEFAULT 'default',
+    UNIQUE (project_id, rfc_slug, branch_name)
+);
+INSERT INTO branch_visibility__new SELECT * FROM branch_visibility;
+DROP TABLE branch_visibility;
+ALTER TABLE branch_visibility__new RENAME TO branch_visibility;
+
+-- ── branch_contribute_grants: UNIQUE (rfc_slug, branch_name, grantee) -> +pid
+CREATE TABLE branch_contribute_grants__new (
+    id              INTEGER PRIMARY KEY AUTOINCREMENT,
+    rfc_slug        TEXT NOT NULL,
+    branch_name     TEXT NOT NULL,
+    grantee_user_id INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    granted_by      INTEGER NOT NULL REFERENCES users(id) ON DELETE SET NULL,
+    granted_at      TEXT NOT NULL DEFAULT (datetime('now')),
+    project_id      TEXT NOT NULL DEFAULT 'default',
+    UNIQUE (project_id, rfc_slug, branch_name, grantee_user_id)
+);
+INSERT INTO branch_contribute_grants__new SELECT * FROM branch_contribute_grants;
+DROP TABLE branch_contribute_grants;
+ALTER TABLE branch_contribute_grants__new RENAME TO branch_contribute_grants;
+CREATE INDEX idx_grants_lookup ON branch_contribute_grants (rfc_slug, branch_name);
+CREATE INDEX idx_grants_grantee ON branch_contribute_grants (grantee_user_id);
+
+-- ── stars: UNIQUE (user_id, rfc_slug) -> +project_id ───────────────────────
+CREATE TABLE stars__new (
+    id          INTEGER PRIMARY KEY AUTOINCREMENT,
+    user_id     INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    rfc_slug    TEXT NOT NULL,
+    starred_at  TEXT NOT NULL DEFAULT (datetime('now')),
+    project_id  TEXT NOT NULL DEFAULT 'default',
+    UNIQUE (project_id, user_id, rfc_slug)
+);
+INSERT INTO stars__new SELECT * FROM stars;
+DROP TABLE stars;
+ALTER TABLE stars__new RENAME TO stars;
+CREATE INDEX idx_stars_user ON stars (user_id);
+CREATE INDEX idx_stars_rfc ON stars (rfc_slug);
+
+-- ── watches: UNIQUE (user_id, rfc_slug) -> +project_id ─────────────────────
+CREATE TABLE watches__new (
+    id                      INTEGER PRIMARY KEY AUTOINCREMENT,
+    user_id                 INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    rfc_slug                TEXT NOT NULL,
+    state                   TEXT NOT NULL CHECK (state IN ('watching', 'following', 'muted')),
+    set_by                  TEXT NOT NULL CHECK (set_by IN ('auto', 'explicit')),
+    set_at                  TEXT NOT NULL DEFAULT (datetime('now')),
+    last_participation_at   TEXT,
+    project_id              TEXT NOT NULL DEFAULT 'default',
+    UNIQUE (project_id, user_id, rfc_slug)
+);
+INSERT INTO watches__new SELECT * FROM watches;
+DROP TABLE watches;
+ALTER TABLE watches__new RENAME TO watches;
+CREATE INDEX idx_watches_user ON watches (user_id);
+CREATE INDEX idx_watches_rfc ON watches (rfc_slug);
+CREATE INDEX idx_watches_decay ON watches (state, last_participation_at);
+
+-- ── pr_seen: UNIQUE (user_id, rfc_slug, pr_number) -> +project_id ──────────
+CREATE TABLE pr_seen__new (
+    id                      INTEGER PRIMARY KEY AUTOINCREMENT,
+    user_id                 INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    rfc_slug                TEXT NOT NULL,
+    pr_number               INTEGER NOT NULL,
+    last_seen_commit_sha    TEXT,
+    last_seen_message_id    INTEGER REFERENCES thread_messages(id) ON DELETE SET NULL,
+    seen_at                 TEXT NOT NULL DEFAULT (datetime('now')),
+    project_id              TEXT NOT NULL DEFAULT 'default',
+    UNIQUE (project_id, user_id, rfc_slug, pr_number)
+);
+INSERT INTO pr_seen__new SELECT * FROM pr_seen;
+DROP TABLE pr_seen;
+ALTER TABLE pr_seen__new RENAME TO pr_seen;
+
+-- ── branch_chat_seen: UNIQUE (user_id, rfc_slug, branch_name) -> +project_id
+CREATE TABLE branch_chat_seen__new (
+    id                      INTEGER PRIMARY KEY AUTOINCREMENT,
+    user_id                 INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    rfc_slug                TEXT NOT NULL,
+    branch_name             TEXT NOT NULL,
+    last_seen_message_id    INTEGER REFERENCES thread_messages(id) ON DELETE SET NULL,
+    seen_at                 TEXT NOT NULL DEFAULT (datetime('now')),
+    project_id              TEXT NOT NULL DEFAULT 'default',
+    UNIQUE (project_id, user_id, rfc_slug, branch_name)
+);
+INSERT INTO branch_chat_seen__new SELECT * FROM branch_chat_seen;
+DROP TABLE branch_chat_seen;
+ALTER TABLE branch_chat_seen__new RENAME TO branch_chat_seen;
+
+-- ── funder_consents: PRIMARY KEY (user_id, rfc_slug) -> +project_id ────────
+CREATE TABLE funder_consents__new (
+    user_id     INTEGER NOT NULL,
+    rfc_slug    TEXT    NOT NULL,
+    created_at  TEXT    NOT NULL DEFAULT (datetime('now')),
+    project_id  TEXT    NOT NULL DEFAULT 'default',
+    PRIMARY KEY (project_id, user_id, rfc_slug),
+    FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE CASCADE
+);
+INSERT INTO funder_consents__new SELECT * FROM funder_consents;
+DROP TABLE funder_consents;
+ALTER TABLE funder_consents__new RENAME TO funder_consents;
+CREATE INDEX idx_funder_consents_slug ON funder_consents (rfc_slug);
+
+-- ── rfc_collaborators: UNIQUE idx (rfc_slug, user_id) -> +project_id;
+--     FK rfc_slug -> cached_rfcs(slug) becomes composite (project_id, rfc_slug)
+CREATE TABLE rfc_collaborators__new (
+    id              INTEGER PRIMARY KEY AUTOINCREMENT,
+    rfc_slug        TEXT NOT NULL,
+    user_id         INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    role_in_rfc     TEXT NOT NULL CHECK (role_in_rfc IN ('contributor', 'discussant')),
+    invitation_id   INTEGER REFERENCES rfc_invitations(id) ON DELETE SET NULL,
+    created_at      TEXT NOT NULL DEFAULT (datetime('now')),
+    project_id      TEXT NOT NULL DEFAULT 'default',
+    FOREIGN KEY (project_id, rfc_slug) REFERENCES cached_rfcs(project_id, slug) ON DELETE CASCADE
+);
+INSERT INTO rfc_collaborators__new SELECT * FROM rfc_collaborators;
+DROP TABLE rfc_collaborators;
+ALTER TABLE rfc_collaborators__new RENAME TO rfc_collaborators;
+CREATE UNIQUE INDEX idx_rfc_collaborators_unique ON rfc_collaborators (project_id, rfc_slug, user_id);
+CREATE INDEX idx_rfc_collaborators_user ON rfc_collaborators (user_id);
+
+-- ── contribution_requests: UNIQUE idx (rfc_slug, requester) WHERE pending
+--     -> +project_id; FK rfc_slug -> cached_rfcs(slug) becomes composite.
+CREATE TABLE contribution_requests__new (
+    id                  INTEGER PRIMARY KEY AUTOINCREMENT,
+    rfc_slug            TEXT NOT NULL,
+    requester_user_id   INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    matched_term        TEXT NOT NULL,
+    who_i_am            TEXT NOT NULL,
+    why                 TEXT NOT NULL,
+    use_case            TEXT,
+    status              TEXT NOT NULL DEFAULT 'pending'
+                            CHECK (status IN ('pending', 'accepted', 'declined')),
+    created_at          TEXT NOT NULL DEFAULT (datetime('now')),
+    decided_at          TEXT,
+    decided_by_user_id  INTEGER REFERENCES users(id) ON DELETE SET NULL,
+    invitation_id       INTEGER REFERENCES rfc_invitations(id) ON DELETE SET NULL,
+    notification_id     INTEGER REFERENCES notifications(id) ON DELETE SET NULL,
+    project_id          TEXT NOT NULL DEFAULT 'default',
+    FOREIGN KEY (project_id, rfc_slug) REFERENCES cached_rfcs(project_id, slug) ON DELETE CASCADE
+);
+INSERT INTO contribution_requests__new SELECT * FROM contribution_requests;
+DROP TABLE contribution_requests;
+ALTER TABLE contribution_requests__new RENAME TO contribution_requests;
+CREATE INDEX idx_contribution_requests_rfc ON contribution_requests(rfc_slug, status);
+CREATE INDEX idx_contribution_requests_requester ON contribution_requests(requester_user_id, status);
+CREATE UNIQUE INDEX idx_contribution_requests_one_open
+    ON contribution_requests(project_id, rfc_slug, requester_user_id)
+    WHERE status = 'pending';
+
+-- ── proposed_use_cases: UNIQUE (scope, pr_number) -> +project_id ───────────
+CREATE TABLE proposed_use_cases__new (
+    id              INTEGER PRIMARY KEY AUTOINCREMENT,
+    scope           TEXT NOT NULL CHECK (scope IN ('rfc', 'pr')),
+    rfc_slug        TEXT NOT NULL,
+    pr_number       INTEGER NOT NULL,
+    use_case        TEXT NOT NULL,
+    created_at      TEXT NOT NULL DEFAULT (datetime('now')),
+    project_id      TEXT NOT NULL DEFAULT 'default',
+    UNIQUE (project_id, scope, pr_number)
+);
+INSERT INTO proposed_use_cases__new SELECT * FROM proposed_use_cases;
+DROP TABLE proposed_use_cases;
+ALTER TABLE proposed_use_cases__new RENAME TO proposed_use_cases;
+CREATE INDEX idx_proposed_use_cases_lookup ON proposed_use_cases (scope, pr_number);
+CREATE INDEX idx_proposed_use_cases_slug ON proposed_use_cases (scope, rfc_slug);

backend/migrations/029_collections.sql

@@ -0,0 +1,427 @@
+-- migrate:no-foreign-keys
+--
+-- §22 three-tier refactor — S1. Insert a *collection* grain beneath project.
+--
+--   (1) a `collections` table beneath `projects`;
+--   (2) move the per-corpus fields (type, initial_state) down from `projects`
+--       (projects keeps id, name, content_repo, visibility, config_json, …);
+--   (3) one default collection per project (id='default' for the standard
+--       single-project deployment, subfolder = repo root), inheriting the
+--       project's type / initial_state / visibility;
+--   (4) re-key the 13 entry-corpus tables (project_id, slug) -> (collection_id,
+--       slug) via the migration-028 rebuild pattern, mapping each row to its
+--       project's default collection by JOIN;
+--   (5) generalise project_members -> memberships(scope_type ∈ {project,
+--       collection}, scope_id, …), collapsing the role enum to {owner,
+--       contributor} (§B.3).
+--
+-- SQLite can't ALTER a PK/UNIQUE in place, so each keyed table is rebuilt by the
+-- official create-copy-drop-rename procedure. FK enforcement is OFF for the file
+-- (the `migrate:no-foreign-keys` marker tells the runner to toggle it and run
+-- foreign_key_check after). cached_rfcs is rebuilt FIRST so the child tables can
+-- re-point their composite FK at its new (collection_id, slug) key.
+--
+-- The tables 026 tagged with project_id but 028 did NOT key (threads, changes,
+-- notifications, actions, pr_resolution_branches, cached_prs) keep project_id —
+-- they carry a project-grain tag, untouched in S1. See
+-- docs/design/2026-06-05-three-tier-projects-collections.md §A.6 / Part E.
+
+-- ── collections: the new typed-corpus grain beneath projects ───────────────
+CREATE TABLE collections (
+    id            TEXT NOT NULL,
+    project_id    TEXT NOT NULL REFERENCES projects(id) ON DELETE CASCADE,
+    type          TEXT NOT NULL DEFAULT 'document'
+                      CHECK (type IN ('document', 'specification', 'bdd')),
+    subfolder     TEXT NOT NULL DEFAULT '',
+    initial_state TEXT NOT NULL DEFAULT 'super-draft'
+                      CHECK (initial_state IN ('super-draft', 'active')),
+    visibility    TEXT NOT NULL DEFAULT 'gated'
+                      CHECK (visibility IN ('gated', 'public', 'unlisted')),
+    name          TEXT,
+    registry_sha  TEXT,
+    created_at    TEXT NOT NULL DEFAULT (datetime('now')),
+    updated_at    TEXT NOT NULL DEFAULT (datetime('now')),
+    PRIMARY KEY (id)
+);
+CREATE INDEX idx_collections_project ON collections(project_id);
+
+-- One default collection per project. id='default' for the standard
+-- single-project deployment (a stable literal across deploy histories); the
+-- project_id is used as a unique fallback id only if a non-standard
+-- multi-project deployment migrates (pre-S5; avoids a PK collision).
+INSERT INTO collections (id, project_id, type, subfolder, initial_state, visibility, name)
+SELECT
+    CASE WHEN (SELECT COUNT(*) FROM projects) <= 1 THEN 'default' ELSE p.id END,
+    p.id, p.type, '', p.initial_state, p.visibility, p.name
+FROM projects p;
+
+-- ── projects: rebuild to DROP the per-corpus fields (type, initial_state) ───
+CREATE TABLE projects__new (
+    id            TEXT PRIMARY KEY,
+    name          TEXT NOT NULL,
+    content_repo  TEXT,
+    visibility    TEXT NOT NULL DEFAULT 'gated'
+                      CHECK (visibility IN ('gated', 'public', 'unlisted')),
+    config_json   TEXT,
+    registry_sha  TEXT,
+    created_at    TEXT NOT NULL DEFAULT (datetime('now')),
+    updated_at    TEXT NOT NULL DEFAULT (datetime('now'))
+);
+INSERT INTO projects__new (id, name, content_repo, visibility, config_json, registry_sha, created_at, updated_at)
+SELECT id, name, content_repo, visibility, config_json, registry_sha, created_at, updated_at FROM projects;
+DROP TABLE projects;
+ALTER TABLE projects__new RENAME TO projects;
+
+-- ── cached_rfcs: PRIMARY KEY (project_id, slug) -> (collection_id, slug) ────
+CREATE TABLE cached_rfcs__new (
+    slug                TEXT NOT NULL,
+    title               TEXT NOT NULL,
+    state               TEXT NOT NULL CHECK (state IN ('super-draft', 'active', 'withdrawn', 'retired')),
+    rfc_id              TEXT,
+    repo                TEXT,
+    proposed_by         TEXT,
+    proposed_at         TEXT,
+    graduated_at        TEXT,
+    graduated_by        TEXT,
+    owners_json         TEXT NOT NULL DEFAULT '[]',
+    arbiters_json       TEXT NOT NULL DEFAULT '[]',
+    tags_json           TEXT NOT NULL DEFAULT '[]',
+    body                TEXT,
+    body_sha            TEXT,
+    last_main_commit_at TEXT,
+    last_entry_commit_at TEXT,
+    updated_at          TEXT NOT NULL DEFAULT (datetime('now')),
+    models_json         TEXT,
+    funder_login        TEXT,
+    proposed_use_case   TEXT,
+    collection_id       TEXT NOT NULL DEFAULT 'default' REFERENCES collections(id),
+    unreviewed          INTEGER NOT NULL DEFAULT 0,
+    reviewed_at         TEXT,
+    reviewed_by         TEXT,
+    PRIMARY KEY (collection_id, slug)
+);
+INSERT INTO cached_rfcs__new
+    (slug, title, state, rfc_id, repo, proposed_by, proposed_at, graduated_at,
+     graduated_by, owners_json, arbiters_json, tags_json, body, body_sha,
+     last_main_commit_at, last_entry_commit_at, updated_at, models_json,
+     funder_login, proposed_use_case, collection_id, unreviewed, reviewed_at, reviewed_by)
+SELECT
+    r.slug, r.title, r.state, r.rfc_id, r.repo, r.proposed_by, r.proposed_at, r.graduated_at,
+    r.graduated_by, r.owners_json, r.arbiters_json, r.tags_json, r.body, r.body_sha,
+    r.last_main_commit_at, r.last_entry_commit_at, r.updated_at, r.models_json,
+    r.funder_login, r.proposed_use_case,
+    (SELECT c.id FROM collections c WHERE c.project_id = r.project_id LIMIT 1),
+    r.unreviewed, r.reviewed_at, r.reviewed_by
+FROM cached_rfcs r;
+DROP TABLE cached_rfcs;
+ALTER TABLE cached_rfcs__new RENAME TO cached_rfcs;
+CREATE INDEX idx_cached_rfcs_state ON cached_rfcs (state);
+CREATE INDEX idx_cached_rfcs_last_active ON cached_rfcs (
+    COALESCE(last_main_commit_at, last_entry_commit_at) DESC
+);
+CREATE INDEX idx_cached_rfcs_collection ON cached_rfcs(collection_id);
+
+-- ── rfc_invitations: single-col FK -> composite (collection_id, rfc_slug) ───
+CREATE TABLE rfc_invitations__new (
+    id                      INTEGER PRIMARY KEY AUTOINCREMENT,
+    rfc_slug                TEXT NOT NULL,
+    inviter_user_id         INTEGER REFERENCES users(id) ON DELETE SET NULL,
+    invitee_email           TEXT NOT NULL,
+    role_in_rfc             TEXT NOT NULL CHECK (role_in_rfc IN ('contributor', 'discussant')),
+    status                  TEXT NOT NULL DEFAULT 'pending'
+        CHECK (status IN ('pending', 'accepted', 'revoked', 'expired')),
+    token                   TEXT NOT NULL,
+    expires_at              TEXT NOT NULL,
+    created_at              TEXT NOT NULL DEFAULT (datetime('now')),
+    accepted_at             TEXT,
+    accepted_by_user_id     INTEGER REFERENCES users(id) ON DELETE SET NULL,
+    collection_id           TEXT NOT NULL DEFAULT 'default',
+    FOREIGN KEY (collection_id, rfc_slug) REFERENCES cached_rfcs(collection_id, slug) ON DELETE CASCADE
+);
+INSERT INTO rfc_invitations__new
+    (id, rfc_slug, inviter_user_id, invitee_email, role_in_rfc, status, token,
+     expires_at, created_at, accepted_at, accepted_by_user_id, collection_id)
+SELECT
+    i.id, i.rfc_slug, i.inviter_user_id, i.invitee_email, i.role_in_rfc, i.status, i.token,
+    i.expires_at, i.created_at, i.accepted_at, i.accepted_by_user_id,
+    (SELECT c.id FROM collections c WHERE c.project_id = i.project_id LIMIT 1)
+FROM rfc_invitations i;
+DROP TABLE rfc_invitations;
+ALTER TABLE rfc_invitations__new RENAME TO rfc_invitations;
+CREATE UNIQUE INDEX idx_rfc_invitations_token ON rfc_invitations (token);
+CREATE INDEX idx_rfc_invitations_rfc_status ON rfc_invitations (rfc_slug, status);
+CREATE INDEX idx_rfc_invitations_email_status ON rfc_invitations (invitee_email, status);
+
+-- ── cached_branches: UNIQUE (project_id, rfc_slug, branch_name) -> collection
+CREATE TABLE cached_branches__new (
+    id              INTEGER PRIMARY KEY AUTOINCREMENT,
+    rfc_slug        TEXT NOT NULL,
+    branch_name     TEXT NOT NULL,
+    head_sha        TEXT,
+    state           TEXT NOT NULL DEFAULT 'open' CHECK (state IN ('open', 'closed', 'deleted')),
+    pinned          INTEGER NOT NULL DEFAULT 0,
+    created_at      TEXT NOT NULL DEFAULT (datetime('now')),
+    last_commit_at  TEXT,
+    closed_at       TEXT,
+    collection_id   TEXT NOT NULL DEFAULT 'default',
+    UNIQUE (collection_id, rfc_slug, branch_name)
+);
+INSERT INTO cached_branches__new
+    (id, rfc_slug, branch_name, head_sha, state, pinned, created_at, last_commit_at, closed_at, collection_id)
+SELECT
+    b.id, b.rfc_slug, b.branch_name, b.head_sha, b.state, b.pinned, b.created_at, b.last_commit_at, b.closed_at,
+    (SELECT c.id FROM collections c WHERE c.project_id = b.project_id LIMIT 1)
+FROM cached_branches b;
+DROP TABLE cached_branches;
+ALTER TABLE cached_branches__new RENAME TO cached_branches;
+CREATE INDEX idx_cached_branches_rfc ON cached_branches (rfc_slug, state);
+
+-- ── branch_visibility: UNIQUE (project_id, rfc_slug, branch_name) -> collection
+CREATE TABLE branch_visibility__new (
+    id              INTEGER PRIMARY KEY AUTOINCREMENT,
+    rfc_slug        TEXT NOT NULL,
+    branch_name     TEXT NOT NULL,
+    read_public     INTEGER NOT NULL DEFAULT 1,
+    contribute_mode TEXT NOT NULL DEFAULT 'just-me' CHECK (contribute_mode IN ('just-me', 'specific', 'any-contributor')),
+    collection_id   TEXT NOT NULL DEFAULT 'default',
+    UNIQUE (collection_id, rfc_slug, branch_name)
+);
+INSERT INTO branch_visibility__new
+    (id, rfc_slug, branch_name, read_public, contribute_mode, collection_id)
+SELECT
+    v.id, v.rfc_slug, v.branch_name, v.read_public, v.contribute_mode,
+    (SELECT c.id FROM collections c WHERE c.project_id = v.project_id LIMIT 1)
+FROM branch_visibility v;
+DROP TABLE branch_visibility;
+ALTER TABLE branch_visibility__new RENAME TO branch_visibility;
+
+-- ── branch_contribute_grants: UNIQUE (..., grantee) -> +collection_id ───────
+CREATE TABLE branch_contribute_grants__new (
+    id              INTEGER PRIMARY KEY AUTOINCREMENT,
+    rfc_slug        TEXT NOT NULL,
+    branch_name     TEXT NOT NULL,
+    grantee_user_id INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    granted_by      INTEGER NOT NULL REFERENCES users(id) ON DELETE SET NULL,
+    granted_at      TEXT NOT NULL DEFAULT (datetime('now')),
+    collection_id   TEXT NOT NULL DEFAULT 'default',
+    UNIQUE (collection_id, rfc_slug, branch_name, grantee_user_id)
+);
+INSERT INTO branch_contribute_grants__new
+    (id, rfc_slug, branch_name, grantee_user_id, granted_by, granted_at, collection_id)
+SELECT
+    g.id, g.rfc_slug, g.branch_name, g.grantee_user_id, g.granted_by, g.granted_at,
+    (SELECT c.id FROM collections c WHERE c.project_id = g.project_id LIMIT 1)
+FROM branch_contribute_grants g;
+DROP TABLE branch_contribute_grants;
+ALTER TABLE branch_contribute_grants__new RENAME TO branch_contribute_grants;
+CREATE INDEX idx_grants_lookup ON branch_contribute_grants (rfc_slug, branch_name);
+CREATE INDEX idx_grants_grantee ON branch_contribute_grants (grantee_user_id);
+
+-- ── stars: UNIQUE (project_id, user_id, rfc_slug) -> collection_id ──────────
+CREATE TABLE stars__new (
+    id          INTEGER PRIMARY KEY AUTOINCREMENT,
+    user_id     INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    rfc_slug    TEXT NOT NULL,
+    starred_at  TEXT NOT NULL DEFAULT (datetime('now')),
+    collection_id  TEXT NOT NULL DEFAULT 'default',
+    UNIQUE (collection_id, user_id, rfc_slug)
+);
+INSERT INTO stars__new (id, user_id, rfc_slug, starred_at, collection_id)
+SELECT s.id, s.user_id, s.rfc_slug, s.starred_at,
+    (SELECT c.id FROM collections c WHERE c.project_id = s.project_id LIMIT 1)
+FROM stars s;
+DROP TABLE stars;
+ALTER TABLE stars__new RENAME TO stars;
+CREATE INDEX idx_stars_user ON stars (user_id);
+CREATE INDEX idx_stars_rfc ON stars (rfc_slug);
+
+-- ── watches: UNIQUE (project_id, user_id, rfc_slug) -> collection_id ────────
+CREATE TABLE watches__new (
+    id                      INTEGER PRIMARY KEY AUTOINCREMENT,
+    user_id                 INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    rfc_slug                TEXT NOT NULL,
+    state                   TEXT NOT NULL CHECK (state IN ('watching', 'following', 'muted')),
+    set_by                  TEXT NOT NULL CHECK (set_by IN ('auto', 'explicit')),
+    set_at                  TEXT NOT NULL DEFAULT (datetime('now')),
+    last_participation_at   TEXT,
+    collection_id           TEXT NOT NULL DEFAULT 'default',
+    UNIQUE (collection_id, user_id, rfc_slug)
+);
+INSERT INTO watches__new
+    (id, user_id, rfc_slug, state, set_by, set_at, last_participation_at, collection_id)
+SELECT
+    w.id, w.user_id, w.rfc_slug, w.state, w.set_by, w.set_at, w.last_participation_at,
+    (SELECT c.id FROM collections c WHERE c.project_id = w.project_id LIMIT 1)
+FROM watches w;
+DROP TABLE watches;
+ALTER TABLE watches__new RENAME TO watches;
+CREATE INDEX idx_watches_user ON watches (user_id);
+CREATE INDEX idx_watches_rfc ON watches (rfc_slug);
+CREATE INDEX idx_watches_decay ON watches (state, last_participation_at);
+
+-- ── pr_seen: UNIQUE (project_id, user_id, rfc_slug, pr_number) -> collection ─
+CREATE TABLE pr_seen__new (
+    id                      INTEGER PRIMARY KEY AUTOINCREMENT,
+    user_id                 INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    rfc_slug                TEXT NOT NULL,
+    pr_number               INTEGER NOT NULL,
+    last_seen_commit_sha    TEXT,
+    last_seen_message_id    INTEGER REFERENCES thread_messages(id) ON DELETE SET NULL,
+    seen_at                 TEXT NOT NULL DEFAULT (datetime('now')),
+    collection_id           TEXT NOT NULL DEFAULT 'default',
+    UNIQUE (collection_id, user_id, rfc_slug, pr_number)
+);
+INSERT INTO pr_seen__new
+    (id, user_id, rfc_slug, pr_number, last_seen_commit_sha, last_seen_message_id, seen_at, collection_id)
+SELECT
+    p.id, p.user_id, p.rfc_slug, p.pr_number, p.last_seen_commit_sha, p.last_seen_message_id, p.seen_at,
+    (SELECT c.id FROM collections c WHERE c.project_id = p.project_id LIMIT 1)
+FROM pr_seen p;
+DROP TABLE pr_seen;
+ALTER TABLE pr_seen__new RENAME TO pr_seen;
+
+-- ── branch_chat_seen: UNIQUE (project_id, user_id, rfc_slug, branch) -> coll ─
+CREATE TABLE branch_chat_seen__new (
+    id                      INTEGER PRIMARY KEY AUTOINCREMENT,
+    user_id                 INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    rfc_slug                TEXT NOT NULL,
+    branch_name             TEXT NOT NULL,
+    last_seen_message_id    INTEGER REFERENCES thread_messages(id) ON DELETE SET NULL,
+    seen_at                 TEXT NOT NULL DEFAULT (datetime('now')),
+    collection_id           TEXT NOT NULL DEFAULT 'default',
+    UNIQUE (collection_id, user_id, rfc_slug, branch_name)
+);
+INSERT INTO branch_chat_seen__new
+    (id, user_id, rfc_slug, branch_name, last_seen_message_id, seen_at, collection_id)
+SELECT
+    s.id, s.user_id, s.rfc_slug, s.branch_name, s.last_seen_message_id, s.seen_at,
+    (SELECT c.id FROM collections c WHERE c.project_id = s.project_id LIMIT 1)
+FROM branch_chat_seen s;
+DROP TABLE branch_chat_seen;
+ALTER TABLE branch_chat_seen__new RENAME TO branch_chat_seen;
+
+-- ── funder_consents: PRIMARY KEY (project_id, user_id, rfc_slug) -> collection
+CREATE TABLE funder_consents__new (
+    user_id     INTEGER NOT NULL,
+    rfc_slug    TEXT    NOT NULL,
+    created_at  TEXT    NOT NULL DEFAULT (datetime('now')),
+    collection_id  TEXT NOT NULL DEFAULT 'default',
+    PRIMARY KEY (collection_id, user_id, rfc_slug),
+    FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE CASCADE
+);
+INSERT INTO funder_consents__new (user_id, rfc_slug, created_at, collection_id)
+SELECT f.user_id, f.rfc_slug, f.created_at,
+    (SELECT c.id FROM collections c WHERE c.project_id = f.project_id LIMIT 1)
+FROM funder_consents f;
+DROP TABLE funder_consents;
+ALTER TABLE funder_consents__new RENAME TO funder_consents;
+CREATE INDEX idx_funder_consents_slug ON funder_consents (rfc_slug);
+
+-- ── rfc_collaborators: UNIQUE idx + composite FK -> collection_id ───────────
+CREATE TABLE rfc_collaborators__new (
+    id              INTEGER PRIMARY KEY AUTOINCREMENT,
+    rfc_slug        TEXT NOT NULL,
+    user_id         INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    role_in_rfc     TEXT NOT NULL CHECK (role_in_rfc IN ('contributor', 'discussant')),
+    invitation_id   INTEGER REFERENCES rfc_invitations(id) ON DELETE SET NULL,
+    created_at      TEXT NOT NULL DEFAULT (datetime('now')),
+    collection_id   TEXT NOT NULL DEFAULT 'default',
+    FOREIGN KEY (collection_id, rfc_slug) REFERENCES cached_rfcs(collection_id, slug) ON DELETE CASCADE
+);
+INSERT INTO rfc_collaborators__new
+    (id, rfc_slug, user_id, role_in_rfc, invitation_id, created_at, collection_id)
+SELECT
+    rc.id, rc.rfc_slug, rc.user_id, rc.role_in_rfc, rc.invitation_id, rc.created_at,
+    (SELECT c.id FROM collections c WHERE c.project_id = rc.project_id LIMIT 1)
+FROM rfc_collaborators rc;
+DROP TABLE rfc_collaborators;
+ALTER TABLE rfc_collaborators__new RENAME TO rfc_collaborators;
+CREATE UNIQUE INDEX idx_rfc_collaborators_unique ON rfc_collaborators (collection_id, rfc_slug, user_id);
+CREATE INDEX idx_rfc_collaborators_user ON rfc_collaborators (user_id);
+
+-- ── contribution_requests: UNIQUE idx (pending) + composite FK -> collection ─
+CREATE TABLE contribution_requests__new (
+    id                  INTEGER PRIMARY KEY AUTOINCREMENT,
+    rfc_slug            TEXT NOT NULL,
+    requester_user_id   INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    matched_term        TEXT NOT NULL,
+    who_i_am            TEXT NOT NULL,
+    why                 TEXT NOT NULL,
+    use_case            TEXT,
+    status              TEXT NOT NULL DEFAULT 'pending'
+                            CHECK (status IN ('pending', 'accepted', 'declined')),
+    created_at          TEXT NOT NULL DEFAULT (datetime('now')),
+    decided_at          TEXT,
+    decided_by_user_id  INTEGER REFERENCES users(id) ON DELETE SET NULL,
+    invitation_id       INTEGER REFERENCES rfc_invitations(id) ON DELETE SET NULL,
+    notification_id     INTEGER REFERENCES notifications(id) ON DELETE SET NULL,
+    collection_id       TEXT NOT NULL DEFAULT 'default',
+    FOREIGN KEY (collection_id, rfc_slug) REFERENCES cached_rfcs(collection_id, slug) ON DELETE CASCADE
+);
+INSERT INTO contribution_requests__new
+    (id, rfc_slug, requester_user_id, matched_term, who_i_am, why, use_case, status,
+     created_at, decided_at, decided_by_user_id, invitation_id, notification_id, collection_id)
+SELECT
+    cr.id, cr.rfc_slug, cr.requester_user_id, cr.matched_term, cr.who_i_am, cr.why, cr.use_case, cr.status,
+    cr.created_at, cr.decided_at, cr.decided_by_user_id, cr.invitation_id, cr.notification_id,
+    (SELECT c.id FROM collections c WHERE c.project_id = cr.project_id LIMIT 1)
+FROM contribution_requests cr;
+DROP TABLE contribution_requests;
+ALTER TABLE contribution_requests__new RENAME TO contribution_requests;
+CREATE INDEX idx_contribution_requests_rfc ON contribution_requests(rfc_slug, status);
+CREATE INDEX idx_contribution_requests_requester ON contribution_requests(requester_user_id, status);
+CREATE UNIQUE INDEX idx_contribution_requests_one_open
+    ON contribution_requests(collection_id, rfc_slug, requester_user_id)
+    WHERE status = 'pending';
+
+-- ── proposed_use_cases: UNIQUE (project_id, scope, pr_number) -> collection ──
+CREATE TABLE proposed_use_cases__new (
+    id              INTEGER PRIMARY KEY AUTOINCREMENT,
+    scope           TEXT NOT NULL CHECK (scope IN ('rfc', 'pr')),
+    rfc_slug        TEXT NOT NULL,
+    pr_number       INTEGER NOT NULL,
+    use_case        TEXT NOT NULL,
+    created_at      TEXT NOT NULL DEFAULT (datetime('now')),
+    collection_id   TEXT NOT NULL DEFAULT 'default',
+    UNIQUE (collection_id, scope, pr_number)
+);
+INSERT INTO proposed_use_cases__new
+    (id, scope, rfc_slug, pr_number, use_case, created_at, collection_id)
+SELECT
+    u.id, u.scope, u.rfc_slug, u.pr_number, u.use_case, u.created_at,
+    (SELECT c.id FROM collections c WHERE c.project_id = u.project_id LIMIT 1)
+FROM proposed_use_cases u;
+DROP TABLE proposed_use_cases;
+ALTER TABLE proposed_use_cases__new RENAME TO proposed_use_cases;
+CREATE INDEX idx_proposed_use_cases_lookup ON proposed_use_cases (scope, pr_number);
+CREATE INDEX idx_proposed_use_cases_slug ON proposed_use_cases (scope, rfc_slug);
+
+-- ── project_members -> memberships(scope_type, scope_id, …); roles collapsed ─
+CREATE TABLE memberships (
+    id          INTEGER PRIMARY KEY AUTOINCREMENT,
+    scope_type  TEXT NOT NULL CHECK (scope_type IN ('project', 'collection')),
+    scope_id    TEXT NOT NULL,
+    user_id     INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    role        TEXT NOT NULL CHECK (role IN ('owner', 'contributor')),
+    granted_by  INTEGER REFERENCES users(id) ON DELETE SET NULL,
+    granted_at  TEXT NOT NULL DEFAULT (datetime('now')),
+    UNIQUE (scope_type, scope_id, user_id)
+);
+CREATE INDEX idx_memberships_user ON memberships(user_id);
+CREATE INDEX idx_memberships_scope ON memberships(scope_type, scope_id);
+
+-- M2 project_members rows attached at what is now the *collection*; collapse the
+-- role enum (project_admin -> owner, project_contributor -> contributor;
+-- project_viewer dropped this pass, §B.3) and migrate onto the default
+-- collection of each project.
+INSERT INTO memberships (scope_type, scope_id, user_id, role, granted_by, granted_at)
+SELECT 'collection',
+       (SELECT c.id FROM collections c WHERE c.project_id = pm.project_id LIMIT 1),
+       pm.user_id,
+       CASE pm.role WHEN 'project_admin' THEN 'owner'
+                    WHEN 'project_contributor' THEN 'contributor'
+                    ELSE 'contributor' END,
+       pm.granted_by, pm.granted_at
+FROM project_members pm
+WHERE pm.role IN ('project_admin', 'project_contributor');
+DROP TABLE project_members;

backend/migrations/030_global_scope.sql

@@ -0,0 +1,34 @@
+-- migrate:no-foreign-keys
+--
+-- §22 three-tier — S3. Admit a *global*-scope grant to the memberships table.
+--
+-- §B.2's resolver folds four layers (global → project → collection → per-entry).
+-- Migration 029 created `memberships` with scope_type ∈ {project, collection}
+-- only; the global tier was left to S3. A global grant is how a "global RFC
+-- Contributor" (a contributor who may propose in every collection of every
+-- project, distinct from a deployment owner/admin) is represented — see
+-- docs/design/2026-06-05-three-tier-projects-collections.md §B.2/§B.3 and the
+-- C.1 "cleo" scenario.
+--
+-- SQLite can't ALTER a CHECK constraint in place, so the table is rebuilt by the
+-- create-copy-drop-rename procedure (the 028/029 pattern). The global scope uses
+-- a stable sentinel scope_id of '*' (one global tier per deployment); the
+-- UNIQUE(scope_type, scope_id, user_id) then admits exactly one global grant per
+-- user, mirroring the project/collection rows.
+
+CREATE TABLE memberships__new (
+    id          INTEGER PRIMARY KEY AUTOINCREMENT,
+    scope_type  TEXT NOT NULL CHECK (scope_type IN ('global', 'project', 'collection')),
+    scope_id    TEXT NOT NULL,
+    user_id     INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    role        TEXT NOT NULL CHECK (role IN ('owner', 'contributor')),
+    granted_by  INTEGER REFERENCES users(id) ON DELETE SET NULL,
+    granted_at  TEXT NOT NULL DEFAULT (datetime('now')),
+    UNIQUE (scope_type, scope_id, user_id)
+);
+INSERT INTO memberships__new (id, scope_type, scope_id, user_id, role, granted_by, granted_at)
+SELECT id, scope_type, scope_id, user_id, role, granted_by, granted_at FROM memberships;
+DROP TABLE memberships;
+ALTER TABLE memberships__new RENAME TO memberships;
+CREATE INDEX idx_memberships_user ON memberships(user_id);
+CREATE INDEX idx_memberships_scope ON memberships(scope_type, scope_id);

backend/migrations/031_collection_enabled_models.sql

@@ -0,0 +1,9 @@
+-- §22.12 S6 — per-collection model universe.
+--
+-- A collection's `.collection.yaml` may carry an `enabled_models` list that
+-- NARROWS its project's universe (which narrows the deployment ENABLED_MODELS).
+-- Mirrored into a `config_json` blob on the collection row, paralleling
+-- `projects.config_json` (which already holds the project's enabled_models +
+-- theme). Additive only — no rebuild. NULL means "no per-collection narrowing;
+-- inherit the project's universe."
+ALTER TABLE collections ADD COLUMN config_json TEXT;

backend/migrations/032_join_requests.sql

@@ -0,0 +1,58 @@
+-- §22.8 S6 — request-to-join a scope + the cross-collection inbox.
+--
+-- A gated project or collection is invisible to non-members (§22.5), so a user
+-- who knows a scope exists can ask to join it: they name a desired role and the
+-- request is recorded here, then fanned out to that scope's Owners *across the
+-- subtree* (a collection request reaches the collection's Owners, its project's
+-- Owners, and global Owners — the cross-collection inbox, §22.11). An Owner
+-- accepts (which writes the `memberships` row via memberships.grant) or declines;
+-- the requester is §15-notified of the decision either way.
+--
+-- This mirrors `contribution_requests` (migration 024) but at the scope grain
+-- instead of the per-RFC grain: the target is a `(scope_type, scope_id)` pair
+-- (matching the `memberships` scope vocabulary, minus 'global' — joining is for a
+-- project or collection a user discovers, not the deployment), and accept grants
+-- a scope role rather than minting an RFC invitation.
+--
+-- The request row is the persistent record; the inbox notification is the
+-- owner-facing actionable surface keyed back to it via `notification_id`.
+
+CREATE TABLE IF NOT EXISTS join_requests (
+    id                  INTEGER PRIMARY KEY AUTOINCREMENT,
+    -- The target scope. 'global' is intentionally excluded: the deployment is
+    -- not a thing one "discovers and joins" (§22.8 names a project/collection).
+    scope_type          TEXT NOT NULL
+                            CHECK (scope_type IN ('project', 'collection')),
+    scope_id            TEXT NOT NULL,
+    requester_user_id   INTEGER NOT NULL
+                            REFERENCES users(id) ON DELETE CASCADE,
+    -- The role the requester is asking for ({owner, contributor}, the §22.6
+    -- unified vocabulary). The accepting Owner may grant this or a narrower role.
+    requested_role      TEXT NOT NULL
+                            CHECK (requested_role IN ('owner', 'contributor')),
+    -- Optional free text — "who I am / why I want in". Bounded by the API layer.
+    message             TEXT,
+    status              TEXT NOT NULL DEFAULT 'pending'
+                            CHECK (status IN ('pending', 'accepted', 'declined')),
+    created_at          TEXT NOT NULL DEFAULT (datetime('now')),
+    decided_at          TEXT,
+    decided_by_user_id  INTEGER REFERENCES users(id) ON DELETE SET NULL,
+    -- The role actually granted on accept (may differ from requested_role if the
+    -- Owner narrowed it); NULL until accepted.
+    granted_role        TEXT CHECK (granted_role IN ('owner', 'contributor')),
+    -- The owner-facing notification row that carries the Accept/Decline action.
+    notification_id     INTEGER REFERENCES notifications(id) ON DELETE SET NULL
+);
+
+CREATE INDEX IF NOT EXISTS idx_join_requests_scope
+    ON join_requests(scope_type, scope_id, status);
+
+CREATE INDEX IF NOT EXISTS idx_join_requests_requester
+    ON join_requests(requester_user_id, status);
+
+-- At most one open (pending) request per (scope, requester): a second ask while
+-- one is still pending is a 409, not a duplicate row. A decided request
+-- (accepted/declined) does not block a fresh ask later.
+CREATE UNIQUE INDEX IF NOT EXISTS idx_join_requests_one_open
+    ON join_requests(scope_type, scope_id, requester_user_id)
+    WHERE status = 'pending';

backend/tests/conftest.py

@@ -0,0 +1,19 @@
+"""Shared pytest fixtures for the backend suite.
+
+Added in v0.27.0 (security audit 0026) alongside the new per-IP rate
+limiter. The limiters in `app.ratelimit` are process-global singletons,
+so their state survives across tests within a run; without a reset, the
+accumulated requests from earlier tests exhaust the budget and later
+tests see spurious 429s. This autouse fixture gives every test a clean
+limiter window.
+"""
+import pytest
+
+from app import ratelimit
+
+
+@pytest.fixture(autouse=True)
+def _reset_rate_limiters():
+    ratelimit._reset_all_for_tests()
+    yield
+    ratelimit._reset_all_for_tests()

backend/tests/test_api_deployment.py

@@ -0,0 +1,139 @@
+"""§22.9/§22.5 — GET /api/deployment + GET /api/projects/:id with visibility."""
+from __future__ import annotations
+
+from fastapi.testclient import TestClient
+
+from test_propose_vertical import (  # noqa: F401
+    app_with_fake_gitea, tmp_env, provision_user_row, sign_in_as,
+)
+
+
+def _add_project(pid, name, vis, typ="document"):
+    # §22 three-tier: a project (grouping tier) + its default collection (the
+    # per-corpus type/initial_state moved down in migration 029). The default
+    # collection keys by the project id so it is globally unique in tests.
+    from app import db
+    db.conn().execute(
+        "INSERT OR REPLACE INTO projects (id, name, content_repo, visibility) VALUES (?, ?, ?, ?)",
+        (pid, name, pid, vis),
+    )
+    db.conn().execute(
+        "INSERT OR REPLACE INTO collections (id, project_id, type, subfolder, initial_state, visibility, name) "
+        "VALUES (?, ?, ?, '', 'super-draft', ?, ?)",
+        (pid, pid, typ, vis, name),
+    )
+
+
+def test_deployment_lists_public_omits_gated_and_unlisted_for_anon(app_with_fake_gitea):
+    app, _ = app_with_fake_gitea
+    with TestClient(app) as client:
+        _add_project("pub", "Public", "public")
+        _add_project("gat", "Gated", "gated")
+        _add_project("unl", "Unlisted", "unlisted")
+        r = client.get("/api/deployment")
+        assert r.status_code == 200
+        body = r.json()
+        assert body["name"] == "Test Deployment"
+        ids = {p["id"] for p in body["projects"]}
+        assert "pub" in ids and "default" in ids  # both public
+        assert "gat" not in ids                    # gated, anon not a member
+        assert "unl" not in ids                    # unlisted never enumerated
+
+
+def test_projects_id_404_for_gated_non_member(app_with_fake_gitea):
+    app, _ = app_with_fake_gitea
+    with TestClient(app) as client:
+        _add_project("gat", "Gated", "gated")
+        assert client.get("/api/projects/gat").status_code == 404
+
+
+def test_projects_id_returns_config_for_public(app_with_fake_gitea):
+    app, _ = app_with_fake_gitea
+    with TestClient(app) as client:
+        from app import db
+        db.conn().execute(
+            "UPDATE projects SET config_json = ? WHERE id = 'default'",
+            ('{"theme": {"accent": "#5b5bd6"}}',),
+        )
+        r = client.get("/api/projects/default")
+        assert r.status_code == 200
+        body = r.json()
+        assert body["id"] == "default"
+        assert body["type"] == "document"
+        assert body["visibility"] == "public"
+        assert body["theme"] == {"accent": "#5b5bd6"}
+
+
+def test_projects_id_unlisted_readable_by_direct_id(app_with_fake_gitea):
+    app, _ = app_with_fake_gitea
+    with TestClient(app) as client:
+        _add_project("unl", "Unlisted", "unlisted")
+        assert client.get("/api/projects/unl").status_code == 200
+
+
+def test_projects_id_unknown_returns_404_even_for_superuser(app_with_fake_gitea):
+    app, _ = app_with_fake_gitea
+    with TestClient(app) as client:
+        provision_user_row(user_id=1, login="ben", role="owner")
+        sign_in_as(client, user_id=1, gitea_login="ben", display_name="Ben", role="owner")
+        assert client.get("/api/projects/does-not-exist").status_code == 404
+
+
+def test_projects_id_unknown_returns_404_for_anon(app_with_fake_gitea):
+    app, _ = app_with_fake_gitea
+    with TestClient(app) as client:
+        assert client.get("/api/projects/nope").status_code == 404
+
+
+def test_deployment_includes_default_project_id(app_with_fake_gitea):
+    # §22.10 / M3-frontend guard contract: the frontend learns which project
+    # is the corpus-served (default) one from the deployment payload.
+    app, _ = app_with_fake_gitea
+    with TestClient(app) as client:
+        body = client.get("/api/deployment").json()
+        assert body["default_project_id"] == "default"
+
+
+def test_rfc_root_url_redirects_308_to_project_scoped(app_with_fake_gitea):
+    # §22.10 / §5: old corpus-root /rfc/<slug> → 308 /p/<default>/e/<slug>.
+    app, _ = app_with_fake_gitea
+    with TestClient(app) as client:
+        r = client.get("/rfc/human", follow_redirects=False)
+        assert r.status_code == 308
+        assert r.headers["location"] == "/p/default/c/default/e/human"
+
+
+def test_rfc_pr_url_redirects_308_to_project_scoped(app_with_fake_gitea):
+    # The old per-RFC PR deep link is preserved too.
+    app, _ = app_with_fake_gitea
+    with TestClient(app) as client:
+        r = client.get("/rfc/human/pr/7", follow_redirects=False)
+        assert r.status_code == 308
+        assert r.headers["location"] == "/p/default/c/default/e/human/pr/7"
+
+
+def test_proposals_root_url_redirects_308_to_project_scoped(app_with_fake_gitea):
+    app, _ = app_with_fake_gitea
+    with TestClient(app) as client:
+        r = client.get("/proposals/42", follow_redirects=False)
+        assert r.status_code == 308
+        assert r.headers["location"] == "/p/default/c/default/proposals/42"
+
+
+def test_gated_project_visible_and_readable_to_member(app_with_fake_gitea):
+    from app import db
+    app, _ = app_with_fake_gitea
+    with TestClient(app) as client:
+        _add_project("teamx", "Team X", "gated")
+        provision_user_row(user_id=5, login="mia", role="contributor")
+        db.conn().execute(
+            "INSERT INTO memberships (scope_type, scope_id, user_id, role) VALUES ('collection', 'teamx', 5, 'contributor')"
+        )
+        sign_in_as(client, user_id=5, gitea_login="mia", display_name="Mia", role="contributor")
+        # member sees the gated project in the deployment directory
+        ids = {p["id"] for p in client.get("/api/deployment").json()["projects"]}
+        assert "teamx" in ids
+        # member can read it directly
+        r = client.get("/api/projects/teamx")
+        assert r.status_code == 200
+        assert r.json()["id"] == "teamx"

backend/tests/test_cache_review_fields.py

@@ -0,0 +1,24 @@
+"""§22.4c — _upsert_cached_rfc mirrors the review fields into cached_rfcs."""
+from __future__ import annotations
+
+from fastapi.testclient import TestClient
+
+from test_propose_vertical import app_with_fake_gitea, tmp_env  # noqa: F401
+
+
+def test_upsert_writes_review_fields(app_with_fake_gitea):
+    from app import cache, db, entry as entry_mod
+
+    app, _ = app_with_fake_gitea
+    with TestClient(app):
+        e = entry_mod.Entry(
+            slug="rev", title="Rev", state="active",
+            unreviewed=True, reviewed_at="2026-06-03", reviewed_by="ben",
+        )
+        cache._upsert_cached_rfc(e, body_sha="sha-rev")
+        row = db.conn().execute(
+            "SELECT unreviewed, reviewed_at, reviewed_by FROM cached_rfcs WHERE slug = 'rev'"
+        ).fetchone()
+        assert row["unreviewed"] == 1
+        assert row["reviewed_at"] == "2026-06-03"
+        assert row["reviewed_by"] == "ben"

backend/tests/test_collection_create_vertical.py

@@ -0,0 +1,83 @@
+"""§22 S2 — create-collection vertical: a deployment owner/admin POSTs, the bot
+commits a `.collection.yaml`, and the registry mirror upserts the collections
+row (registry stays the source of truth)."""
+from __future__ import annotations
+
+from fastapi.testclient import TestClient
+
+from app import db
+from test_propose_vertical import (  # noqa: F401
+    app_with_fake_gitea, tmp_env, provision_user_row, sign_in_as,
+)
+
+
+def test_create_collection_commits_manifest_and_mirrors(app_with_fake_gitea):
+    app, fake = app_with_fake_gitea
+    with TestClient(app) as client:
+        provision_user_row(user_id=1, login="ben", role="owner")
+        sign_in_as(client, user_id=1, gitea_login="ben", display_name="Ben",
+                   role="owner", email="ben@test")
+        r = client.post("/api/projects/default/collections",
+                        json={"collection_id": "features", "type": "bdd", "name": "Features"})
+        assert r.status_code == 200, r.text
+        assert r.json()["type"] == "bdd"
+
+        # The bot committed the manifest to the content repo's main.
+        f = fake.files.get(("wiggleverse", "meta", "main", "features/.collection.yaml"))
+        assert f is not None
+        assert "type: bdd" in f["content"]
+
+        # The registry refresh mirrored it into a collections row.
+        row = db.conn().execute(
+            "SELECT type, project_id, subfolder FROM collections WHERE id='features'"
+        ).fetchone()
+        assert (row["type"], row["project_id"], row["subfolder"]) == ("bdd", "default", "features")
+
+        # It is now navigable via the directory + scoped serve.
+        items = client.get("/api/projects/default/collections").json()["items"]
+        assert any(c["id"] == "features" for c in items)
+        assert client.get("/api/projects/default/collections/features/rfcs").status_code == 200
+
+
+def test_create_collection_requires_admin(app_with_fake_gitea):
+    app, _ = app_with_fake_gitea
+    with TestClient(app) as client:
+        provision_user_row(user_id=2, login="alice", role="contributor")
+        sign_in_as(client, user_id=2, gitea_login="alice", display_name="Alice",
+                   role="contributor", email="alice@test")
+        r = client.post("/api/projects/default/collections",
+                        json={"collection_id": "x", "type": "bdd"})
+        assert r.status_code in (401, 403)
+
+
+def test_create_collection_anonymous_rejected(app_with_fake_gitea):
+    app, _ = app_with_fake_gitea
+    with TestClient(app) as client:
+        r = client.post("/api/projects/default/collections",
+                        json={"collection_id": "x", "type": "bdd"})
+        assert r.status_code in (401, 403)
+
+
+def test_create_collection_rejects_duplicate(app_with_fake_gitea):
+    app, _ = app_with_fake_gitea
+    with TestClient(app) as client:
+        provision_user_row(user_id=1, login="ben", role="owner")
+        sign_in_as(client, user_id=1, gitea_login="ben", display_name="Ben",
+                   role="owner", email="ben@test")
+        ok = client.post("/api/projects/default/collections",
+                         json={"collection_id": "features", "type": "bdd"})
+        assert ok.status_code == 200, ok.text
+        dup = client.post("/api/projects/default/collections",
+                          json={"collection_id": "features", "type": "bdd"})
+        assert dup.status_code == 409
+
+
+def test_create_collection_rejects_reserved_default_id(app_with_fake_gitea):
+    app, _ = app_with_fake_gitea
+    with TestClient(app) as client:
+        provision_user_row(user_id=1, login="ben", role="owner")
+        sign_in_as(client, user_id=1, gitea_login="ben", display_name="Ben",
+                   role="owner", email="ben@test")
+        r = client.post("/api/projects/default/collections",
+                        json={"collection_id": "default", "type": "bdd"})
+        assert r.status_code == 422

backend/tests/test_collection_helpers.py

@@ -0,0 +1,64 @@
+"""§22 S2 — collection read helpers: list_collections / get_collection /
+subfolder_of."""
+from __future__ import annotations
+
+import tempfile
+from pathlib import Path
+
+from app import collections as collections_mod, db
+from app.config import Config
+
+
+def _db() -> Config:
+    cfg = Config(
+        gitea_url="x", gitea_bot_user="x", gitea_bot_token="x", gitea_org="x",
+        registry_repo="registry", oauth_client_id="x",
+        oauth_client_secret="x", app_url="x", secret_key="x",
+        database_path=Path(tempfile.mkdtemp(prefix="colhelp-")) / "t.db",
+        owner_gitea_login="x", webhook_secret="x",
+    )
+    db.run_migrations(cfg)
+    if db._CONN is not None:
+        db._CONN.close()
+        db._CONN = None
+    db.init(cfg)
+    return cfg
+
+
+def _seed(project_id="ohm"):
+    db.conn().execute(
+        "INSERT OR REPLACE INTO projects (id, name, content_repo, visibility, updated_at) "
+        "VALUES (?, 'Ohm', 'ohm-rfc', 'public', datetime('now'))", (project_id,))
+    for cid, sub, vis, name in [
+        ("default", "", "public", "Model"),
+        ("features", "features", "public", "Features"),
+        ("secret", "secret", "unlisted", "Secret"),
+    ]:
+        db.conn().execute(
+            "INSERT OR REPLACE INTO collections (id, project_id, type, subfolder, initial_state, "
+            "visibility, name, created_at, updated_at) VALUES (?,?, 'document', ?, "
+            "'super-draft', ?, ?, datetime('now'), datetime('now'))",
+            (cid, project_id, sub, vis, name))
+
+
+def test_list_collections_excludes_unlisted():
+    _db()
+    _seed()
+    ids = [c["id"] for c in collections_mod.list_collections("ohm", include_unlisted=False)]
+    assert ids == ["default", "features"]  # default first, then by name; 'secret' omitted
+
+
+def test_list_collections_include_unlisted():
+    _db()
+    _seed()
+    ids = {c["id"] for c in collections_mod.list_collections("ohm", include_unlisted=True)}
+    assert ids == {"default", "features", "secret"}
+
+
+def test_get_collection_and_subfolder():
+    _db()
+    _seed()
+    assert collections_mod.get_collection("features")["name"] == "Features"
+    assert collections_mod.subfolder_of("features") == "features"
+    assert collections_mod.subfolder_of("default") == ""
+    assert collections_mod.get_collection("nope") is None

backend/tests/test_collection_registry.py

@@ -0,0 +1,146 @@
+"""§22 S2 — the registry mirror reads `.collection.yaml` manifests inside each
+project's content repo and upserts a named collection per manifest. The default
+collection still flows from projects.yaml (test_registry.py)."""
+from __future__ import annotations
+
+import asyncio
+import base64
+import tempfile
+from pathlib import Path
+
+import pytest
+
+from app import db, registry
+from app.config import Config
+
+
+def _db() -> Config:
+    cfg = Config(
+        gitea_url="x", gitea_bot_user="x", gitea_bot_token="x", gitea_org="wiggleverse",
+        registry_repo="registry", oauth_client_id="x",
+        oauth_client_secret="x", app_url="x", secret_key="x",
+        database_path=Path(tempfile.mkdtemp(prefix="colreg-")) / "t.db",
+        owner_gitea_login="x", webhook_secret="x",
+    )
+    db.run_migrations(cfg)
+    if db._CONN is not None:
+        db._CONN.close()
+        db._CONN = None
+    db.init(cfg)
+    return cfg
+
+
+# --- pure parser --------------------------------------------------------------
+
+
+def test_parse_collection_manifest_minimal():
+    doc = registry.parse_collection_manifest("type: bdd\n")
+    assert doc.type == "bdd"
+    # §22.4b: bdd defaults to 'active'; visibility inherits (None == inherit).
+    assert doc.initial_state == "active"
+    assert doc.visibility is None
+    assert doc.name is None
+
+
+def test_parse_collection_manifest_full():
+    doc = registry.parse_collection_manifest(
+        "type: document\nvisibility: public\ninitial_state: active\nname: Model\n"
+    )
+    assert (doc.type, doc.visibility, doc.initial_state, doc.name) == (
+        "document", "public", "active", "Model",
+    )
+
+
+def test_parse_collection_manifest_rejects_bad_type():
+    with pytest.raises(registry.RegistryError):
+        registry.parse_collection_manifest("type: nonsense\n")
+
+
+def test_parse_collection_manifest_rejects_bad_visibility():
+    with pytest.raises(registry.RegistryError):
+        registry.parse_collection_manifest("type: bdd\nvisibility: nope\n")
+
+
+# --- mirror discovery ---------------------------------------------------------
+
+
+class _FakeGitea:
+    """Minimal Gitea stub: projects.yaml in the registry repo + a content repo
+    whose root holds a `features/` subdir carrying a `.collection.yaml`."""
+
+    def __init__(self, projects_yaml: str, repo_tree: dict[str, dict[str, str]]):
+        self._projects_yaml = projects_yaml
+        self._repo_tree = repo_tree  # {repo: {path: text}}
+
+    async def get_contents(self, org, repo, path, ref="main"):
+        if path == "projects.yaml":
+            return {"type": "file",
+                    "content": base64.b64encode(self._projects_yaml.encode()).decode(),
+                    "sha": "regsha-test"}
+        text = self._repo_tree.get(repo, {}).get(path)
+        if text is None:
+            return None
+        return {"type": "file",
+                "content": base64.b64encode(text.encode()).decode(), "sha": "c0ffee"}
+
+    async def list_dir(self, org, repo, path, ref="main"):
+        # Root listing: surface each top-level segment as a 'dir' entry.
+        prefix = (path.rstrip("/") + "/") if path else ""
+        dirs = set()
+        for p in self._repo_tree.get(repo, {}):
+            if not p.startswith(prefix):
+                continue
+            rest = p[len(prefix):]
+            if "/" in rest:
+                dirs.add(rest.split("/", 1)[0])
+        return [{"type": "dir", "name": n, "path": prefix + n} for n in sorted(dirs)]
+
+
+_PROJECTS = (
+    "deployment:\n  name: Ohm\n  tagline: t\n"
+    "projects:\n  - id: ohm\n    name: Ohm\n    type: document\n"
+    "    content_repo: ohm-rfc\n    visibility: public\n"
+)
+
+
+def test_refresh_registry_mirrors_named_collection():
+    cfg = _db()
+    gitea = _FakeGitea(
+        projects_yaml=_PROJECTS,
+        repo_tree={"ohm-rfc": {"features/.collection.yaml": "type: bdd\nname: Features\n"}},
+    )
+    asyncio.run(registry.refresh_registry(cfg, gitea))
+    row = db.conn().execute(
+        "SELECT type, subfolder, name, project_id, visibility FROM collections WHERE id='features'"
+    ).fetchone()
+    assert row is not None
+    assert (row["type"], row["subfolder"], row["project_id"]) == ("bdd", "features", "ohm")
+    assert row["name"] == "Features"
+    # visibility inherits the project's (public) when the manifest omits it.
+    assert row["visibility"] == "public"
+
+
+def test_refresh_registry_leaves_default_collection_intact():
+    cfg = _db()
+    gitea = _FakeGitea(
+        projects_yaml=_PROJECTS,
+        repo_tree={"ohm-rfc": {"features/.collection.yaml": "type: bdd\n"}},
+    )
+    asyncio.run(registry.refresh_registry(cfg, gitea))
+    # The default collection (from projects.yaml) and the named one coexist.
+    ids = {r["id"] for r in db.conn().execute("SELECT id FROM collections")}
+    assert {"default", "features"} <= ids
+
+
+def test_refresh_registry_immutable_type_on_named_collection():
+    cfg = _db()
+    gitea = _FakeGitea(
+        projects_yaml=_PROJECTS,
+        repo_tree={"ohm-rfc": {"features/.collection.yaml": "type: bdd\n"}},
+    )
+    asyncio.run(registry.refresh_registry(cfg, gitea))
+    # A later manifest that flips the type is refused (§22.4a immutable type).
+    gitea._repo_tree["ohm-rfc"]["features/.collection.yaml"] = "type: document\n"
+    asyncio.run(registry.refresh_registry(cfg, gitea))
+    t = db.conn().execute("SELECT type FROM collections WHERE id='features'").fetchone()["type"]
+    assert t == "bdd"

backend/tests/test_collection_scoped_serve.py

@@ -0,0 +1,164 @@
+"""§22 S2 — collection-grained corpus mirror + collection-scoped serve/propose.
+
+The mirror test drives cache.refresh_meta_repo against an in-memory content repo
+holding entries under both the default `rfcs/` and a named collection's
+`features/rfcs/`, and asserts cached_rfcs is keyed by the right collection_id."""
+from __future__ import annotations
+
+import asyncio
+import tempfile
+from pathlib import Path
+
+from app import cache, db
+from app.config import Config
+
+
+def _db() -> Config:
+    cfg = Config(
+        gitea_url="x", gitea_bot_user="x", gitea_bot_token="x", gitea_org="wiggleverse",
+        registry_repo="registry", oauth_client_id="x",
+        oauth_client_secret="x", app_url="x", secret_key="x",
+        database_path=Path(tempfile.mkdtemp(prefix="colserve-")) / "t.db",
+        owner_gitea_login="x", webhook_secret="x",
+    )
+    db.run_migrations(cfg)
+    if db._CONN is not None:
+        db._CONN.close()
+        db._CONN = None
+    db.init(cfg)
+    return cfg
+
+
+class _CorpusGitea:
+    """A content repo modelled as a flat {path: text} map, listing files under a
+    directory prefix and reading them back."""
+
+    def __init__(self, tree: dict[str, str]):
+        self._tree = tree
+
+    async def list_dir(self, org, repo, path, ref="main"):
+        out = []
+        prefix = (path.rstrip("/") + "/") if path else ""
+        for p in self._tree:
+            if p.startswith(prefix) and "/" not in p[len(prefix):]:
+                out.append({"type": "file", "name": p.split("/")[-1], "path": p})
+        return out
+
+    async def read_file(self, org, repo, path, ref="main"):
+        t = self._tree.get(path)
+        return (t, "sha-" + path) if t is not None else None
+
+
+def _entry_md(slug, title):
+    return f"---\nslug: {slug}\ntitle: {title}\nstate: active\n---\nbody\n"
+
+
+def _seed_project_with_two_collections():
+    db.conn().execute(
+        "INSERT OR REPLACE INTO projects (id, name, content_repo, visibility, updated_at) "
+        "VALUES ('ohm','Ohm','ohm-rfc','public', datetime('now'))")
+    for cid, sub in [("default", ""), ("features", "features")]:
+        db.conn().execute(
+            "INSERT OR REPLACE INTO collections (id, project_id, type, subfolder, initial_state, "
+            "visibility, created_at, updated_at) VALUES (?, 'ohm','document',?, "
+            "'super-draft','public', datetime('now'), datetime('now'))", (cid, sub))
+
+
+def test_mirror_keys_entries_by_collection():
+    cfg = _db()
+    _seed_project_with_two_collections()
+    gitea = _CorpusGitea({
+        "rfcs/a.md": _entry_md("a", "Default A"),
+        "features/rfcs/b.md": _entry_md("b", "Feature B"),
+    })
+    asyncio.run(cache.refresh_meta_repo(cfg, gitea))
+    got = {(r["collection_id"], r["slug"]) for r in
+           db.conn().execute("SELECT collection_id, slug FROM cached_rfcs")}
+    assert got == {("default", "a"), ("features", "b")}
+
+
+# --- collection-scoped serve + propose (full app) -----------------------------
+
+from fastapi.testclient import TestClient  # noqa: E402
+from test_propose_vertical import (  # noqa: E402,F401
+    app_with_fake_gitea, tmp_env, provision_user_row, sign_in_as,
+)
+
+
+def _add_features_collection(content_repo="meta"):
+    """Add a named 'features' collection (subfolder 'features') under the seeded
+    default project, plus a single entry under features/rfcs/ in the db cache."""
+    db.conn().execute(
+        "INSERT OR REPLACE INTO collections (id, project_id, type, subfolder, "
+        "initial_state, visibility, name, created_at, updated_at) VALUES "
+        "('features','default','document','features','super-draft','public','Features', "
+        "datetime('now'), datetime('now'))")
+
+
+def test_scoped_list_returns_only_that_collection(app_with_fake_gitea):
+    app, fake = app_with_fake_gitea
+    with TestClient(app) as client:
+        _add_features_collection()
+        # Seed one entry under each collection's rfcs dir + mirror them in.
+        fake.files[("wiggleverse", "meta", "main", "rfcs/a.md")] = {
+            "content": _entry_md("a", "Default A"), "sha": "sa"}
+        fake.files[("wiggleverse", "meta", "main", "features/rfcs/b.md")] = {
+            "content": _entry_md("b", "Feature B"), "sha": "sb"}
+        from app import cache as cache_mod, gitea as gitea_mod
+        from app.config import load_config
+        cfg = load_config()
+        asyncio.run(cache_mod.refresh_meta_repo(cfg, gitea_mod.Gitea(cfg)))
+
+        r = client.get("/api/projects/default/collections/features/rfcs")
+        assert r.status_code == 200, r.text
+        assert [i["slug"] for i in r.json()["items"]] == ["b"]
+        # The default collection still serves only its own entry.
+        r2 = client.get("/api/projects/default/collections/default/rfcs")
+        assert [i["slug"] for i in r2.json()["items"]] == ["a"]
+
+
+def test_scoped_propose_writes_into_collection_subfolder(app_with_fake_gitea):
+    app, fake = app_with_fake_gitea
+    with TestClient(app) as client:
+        _add_features_collection()
+        provision_user_row(user_id=3, login="alice", role="contributor")
+        # §22 S3: an explicitly-created collection requires an explicit scope
+        # grant to write (the grandfathered baseline covers only `default`).
+        db.conn().execute(
+            "INSERT OR REPLACE INTO memberships (scope_type, scope_id, user_id, role) "
+            "VALUES ('collection', 'features', 3, 'contributor')")
+        sign_in_as(client, user_id=3, gitea_login="alice", display_name="Alice",
+                   role="contributor", email="alice@test")
+        r = client.post(
+            "/api/projects/default/collections/features/rfcs/propose",
+            json={"title": "New B", "slug": "newb", "pitch": "x", "tags": []})
+        assert r.status_code == 200, r.text
+        # The bot wrote the entry under features/rfcs/, not rfcs/.
+        keys = {(k[1], k[3]) for k in fake.files
+                if k[1] == "meta" and k[3].endswith("newb.md")}
+        assert ("meta", "features/rfcs/newb.md") in keys
+
+
+def test_scoped_routes_404_for_collection_outside_project(app_with_fake_gitea):
+    app, _ = app_with_fake_gitea
+    with TestClient(app) as client:
+        r = client.get("/api/projects/default/collections/nope/rfcs")
+        assert r.status_code == 404
+
+
+def test_s2_anonymous_empty_public_collection(app_with_fake_gitea):
+    """C3.6 (@S2): a public collection with no entries; an anonymous visitor
+    lands on its catalog → an empty catalog (200, no items), and the propose
+    action is not available to them (the propose route rejects anonymous)."""
+    app, _ = app_with_fake_gitea
+    with TestClient(app) as client:
+        _add_features_collection()  # public, no entries
+        # Anonymous (no session cookie) reads the empty catalog — 200, [].
+        r = client.get("/api/projects/default/collections/features/rfcs")
+        assert r.status_code == 200, r.text
+        assert r.json()["items"] == []
+        # No propose action for an anonymous visitor.
+        r2 = client.post(
+            "/api/projects/default/collections/features/rfcs/propose",
+            json={"title": "X", "slug": "x", "pitch": "p", "tags": []})
+        assert r2.status_code == 401

backend/tests/test_contributions_vertical.py

@@ -0,0 +1,236 @@
+"""v0.29.0 / roadmap #28 Parts 2 & 3 — create-RFC offers + contribute-to-
+pending requests.
+
+Two layers, mirroring test_rfc_links_vertical.py:
+
+  * The PR-view scanner surfaces `rfc-pending` (Part 3) and `rfc-candidate`
+    (Part 2) segments alongside Part 1's `rfc` links.
+  * The contribute-request flow end-to-end: a non-owner asks, each owner
+    gets an actionable §15 notification, accept fires #12's invite flow,
+    decline notifies the requester.
+
+Reuses the FakeGitea + seed/session helpers from the existing suites.
+"""
+from __future__ import annotations
+
+import json
+
+from fastapi.testclient import TestClient
+
+from app import db
+
+from test_propose_vertical import (  # noqa: F401
+    FakeGitea,
+    app_with_fake_gitea,
+    provision_user_row,
+    sign_in_as,
+    tmp_env,
+)
+from test_rfc_view_vertical import SEED_BODY, seed_active_rfc
+from test_super_draft_vertical import seed_super_draft
+from test_rfc_links_vertical import _open_pr_on
+
+
+def _set_owner(slug: str, login: str) -> None:
+    db.conn().execute(
+        "UPDATE cached_rfcs SET owners_json = ? WHERE slug = ?",
+        (json.dumps([login]), slug),
+    )
+
+
+def _set_tags(slug: str, tags: list[str]) -> None:
+    db.conn().execute(
+        "UPDATE cached_rfcs SET tags_json = ? WHERE slug = ?",
+        (json.dumps(tags), slug),
+    )
+
+
+def _segs(segments, kind):
+    return [s for s in segments if s["type"] == kind]
+
+
+# ---------------------------------------------------------------------------
+# Part 2 + Part 3 — scanner surfaces on the PR view
+# ---------------------------------------------------------------------------
+
+
+def test_pending_and_candidate_segments_on_pr(app_with_fake_gitea):
+    app, fake = app_with_fake_gitea
+    with TestClient(app) as client:
+        provision_user_row(user_id=2, login="alice", role="contributor")
+        # Host active RFC (OHM — single word, contributes no keys itself)
+        # carrying a multi-word tag with no defining RFC: the Part 2
+        # candidate. And a pending super-draft owned by alice: the Part 3
+        # contribute target.
+        seed_active_rfc(fake, slug="ohm", title="OHM", body=SEED_BODY)
+        _set_tags("ohm", ["memory model", "identity"])
+        seed_super_draft(fake, slug="open-human-model", title="Open Human Model",
+                         pitch="A framework for representing humans.", proposed_by="alice")
+        _set_owner("open-human-model", "alice")
+        sign_in_as(client, user_id=2, gitea_login="alice", display_name="Alice", role="contributor")
+
+        pr_number = _open_pr_on(
+            client, fake, host_slug="ohm",
+            description="This builds on the Open Human Model and the memory model.",
+        )
+        pr = client.get(f"/api/rfcs/ohm/prs/{pr_number}").json()
+        segs = pr["description_segments"]
+
+        pending = _segs(segs, "rfc-pending")
+        assert len(pending) == 1
+        assert pending[0]["slug"] == "open-human-model"
+        assert pending[0]["label"] == "Open Human Model"
+        assert pending[0]["owner"] == "Alice"   # display_name of the owner
+
+        candidate = _segs(segs, "rfc-candidate")
+        assert len(candidate) == 1
+        assert candidate[0]["term"] == "memory model"
+        # "identity" is a single-word tag — deliberately NOT a candidate.
+        assert all("identity" not in s.get("term", "") for s in candidate)
+
+
+# ---------------------------------------------------------------------------
+# Part 3 — the contribute-request flow
+# ---------------------------------------------------------------------------
+
+
+def _seed_pending_owned_by_alice(fake):
+    provision_user_row(user_id=2, login="alice", role="contributor")
+    provision_user_row(user_id=3, login="bob", role="contributor")
+    seed_super_draft(fake, slug="open-human-model", title="Open Human Model",
+                     pitch="A framework.", proposed_by="alice")
+    _set_owner("open-human-model", "alice")
+
+
+_REQUEST = {
+    "matched_term": "Open Human Model",
+    "who_i_am": "Bob, a researcher",
+    "why": "I have relevant prior work to bring.",
+    "use_case": "Building an identity tool.",
+}
+
+
+def test_request_accept_invites_and_notifies(app_with_fake_gitea):
+    app, fake = app_with_fake_gitea
+    with TestClient(app) as client:
+        _seed_pending_owned_by_alice(fake)
+
+        # Bob asks to contribute.
+        sign_in_as(client, user_id=3, gitea_login="bob", display_name="Bob",
+                   role="contributor", email="bob@test")
+        r = client.post("/api/rfcs/open-human-model/contribution-requests", json=_REQUEST)
+        assert r.status_code == 200, r.text
+        request_id = r.json()["id"]
+        assert r.json()["status"] == "pending"
+
+        # A second ask while pending is a 409, not a duplicate row.
+        assert client.post("/api/rfcs/open-human-model/contribution-requests",
+                           json=_REQUEST).status_code == 409
+
+        # Alice (owner) sees the actionable notification with full detail.
+        sign_in_as(client, user_id=2, gitea_login="alice", display_name="Alice",
+                   role="contributor", email="alice@test")
+        inbox = client.get("/api/notifications").json()
+        reqs = [i for i in inbox["items"]
+                if i["event_kind"] == "contribution_request_on_pending_rfc"]
+        assert len(reqs) == 1
+        assert "wants to contribute" in reqs[0]["summary"]
+        assert reqs[0]["extras"]["who_i_am"] == "Bob, a researcher"
+        assert reqs[0]["extras"]["request_id"] == request_id
+
+        # Alice accepts → #12 invitation minted for bob's email.
+        acc = client.post(f"/api/rfcs/open-human-model/contribution-requests/{request_id}/accept")
+        assert acc.status_code == 200, acc.text
+        assert acc.json()["status"] == "accepted"
+        assert acc.json()["invitation_id"]
+
+        inv = db.conn().execute(
+            "SELECT invitee_email, role_in_rfc, status FROM rfc_invitations "
+            "WHERE rfc_slug = 'open-human-model'"
+        ).fetchone()
+        assert inv["invitee_email"] == "bob@test"
+        assert inv["role_in_rfc"] == "contributor"
+        assert inv["status"] == "pending"
+
+        # The request is settled — re-accepting is a 409.
+        assert client.post(
+            f"/api/rfcs/open-human-model/contribution-requests/{request_id}/accept"
+        ).status_code == 409
+
+        # Bob gets the accepted echo in his inbox.
+        sign_in_as(client, user_id=3, gitea_login="bob", display_name="Bob",
+                   role="contributor", email="bob@test")
+        bob_kinds = [i["event_kind"] for i in client.get("/api/notifications").json()["items"]]
+        assert "contribution_request_accepted" in bob_kinds
+
+
+def test_decline_notifies_requester(app_with_fake_gitea):
+    app, fake = app_with_fake_gitea
+    with TestClient(app) as client:
+        _seed_pending_owned_by_alice(fake)
+        sign_in_as(client, user_id=3, gitea_login="bob", display_name="Bob",
+                   role="contributor", email="bob@test")
+        request_id = client.post(
+            "/api/rfcs/open-human-model/contribution-requests", json=_REQUEST
+        ).json()["id"]
+
+        sign_in_as(client, user_id=2, gitea_login="alice", display_name="Alice",
+                   role="contributor", email="alice@test")
+        dec = client.post(f"/api/rfcs/open-human-model/contribution-requests/{request_id}/decline")
+        assert dec.status_code == 200, dec.text
+        assert dec.json()["status"] == "declined"
+
+        row = db.conn().execute(
+            "SELECT status FROM contribution_requests WHERE id = ?", (request_id,)
+        ).fetchone()
+        assert row["status"] == "declined"
+
+        sign_in_as(client, user_id=3, gitea_login="bob", display_name="Bob",
+                   role="contributor", email="bob@test")
+        bob_kinds = [i["event_kind"] for i in client.get("/api/notifications").json()["items"]]
+        assert "contribution_request_declined" in bob_kinds
+
+
+def test_owner_cannot_request_own_rfc(app_with_fake_gitea):
+    app, fake = app_with_fake_gitea
+    with TestClient(app) as client:
+        _seed_pending_owned_by_alice(fake)
+        sign_in_as(client, user_id=2, gitea_login="alice", display_name="Alice",
+                   role="contributor", email="alice@test")
+        r = client.post("/api/rfcs/open-human-model/contribution-requests", json=_REQUEST)
+        assert r.status_code == 409
+        assert "own" in r.json()["detail"].lower()
+
+
+def test_request_on_active_rfc_rejected(app_with_fake_gitea):
+    # The contribute offer only exists for pending super-drafts; an active
+    # RFC uses the Part-1 link instead.
+    app, fake = app_with_fake_gitea
+    with TestClient(app) as client:
+        provision_user_row(user_id=3, login="bob", role="contributor")
+        seed_active_rfc(fake, slug="ohm", title="OHM", body=SEED_BODY)
+        sign_in_as(client, user_id=3, gitea_login="bob", display_name="Bob",
+                   role="contributor", email="bob@test")
+        r = client.post("/api/rfcs/ohm/contribution-requests", json=_REQUEST)
+        assert r.status_code == 409
+
+
+def test_contribution_target_eligibility(app_with_fake_gitea):
+    app, fake = app_with_fake_gitea
+    with TestClient(app) as client:
+        _seed_pending_owned_by_alice(fake)
+
+        # Anonymous: not eligible, told to sign in.
+        t = client.get("/api/rfcs/open-human-model/contribution-target").json()
+        assert t["eligible"] is False
+        assert "sign in" in (t["reason"] or "").lower()
+        assert t["owner"] == "Alice"
+
+        # Bob: eligible until he has a pending ask, then not.
+        sign_in_as(client, user_id=3, gitea_login="bob", display_name="Bob",
+                   role="contributor", email="bob@test")
+        assert client.get("/api/rfcs/open-human-model/contribution-target").json()["eligible"] is True
+        client.post("/api/rfcs/open-human-model/contribution-requests", json=_REQUEST)
+        after = client.get("/api/rfcs/open-human-model/contribution-target").json()
+        assert after["already_requested"] is True
+        assert after["eligible"] is False

backend/tests/test_create_project_vertical.py

@@ -0,0 +1,202 @@
+"""§22 S5 — create-project vertical: a global Owner POSTs `/api/projects`, the
+bot provisions a Gitea content repo + commits the project to `projects.yaml`, and
+the registry mirror upserts the `projects` + default `collections` rows (registry
+stays the source of truth). Plus the deployment-directory empty-state signals
+(`viewer.can_create_project`, `default_project_readable`) that drive C3.1/C3.2.
+"""
+from __future__ import annotations
+
+from fastapi.testclient import TestClient
+
+from app import db
+from test_propose_vertical import (  # noqa: F401
+    app_with_fake_gitea, tmp_env, provision_user_row, sign_in_as,
+)
+
+
+def test_create_project_provisions_repo_commits_registry_and_mirrors(app_with_fake_gitea):
+    app, fake = app_with_fake_gitea
+    with TestClient(app) as client:
+        provision_user_row(user_id=1, login="ben", role="owner")
+        sign_in_as(client, user_id=1, gitea_login="ben", display_name="Ben",
+                   role="owner", email="ben@test")
+        r = client.post("/api/projects",
+                        json={"project_id": "acme", "name": "Acme", "type": "bdd",
+                              "visibility": "public"})
+        assert r.status_code == 200, r.text
+        body = r.json()
+        assert body["id"] == "acme"
+        assert body["type"] == "bdd"
+        assert body["visibility"] == "public"
+
+        # The bot provisioned the content repo (default name <id>-content) and
+        # seeded a README so `main` exists.
+        assert ("wiggleverse", "acme-content") in fake.repos
+        readme = fake.files.get(("wiggleverse", "acme-content", "main", "README.md"))
+        assert readme is not None and "acme" in readme["content"]
+
+        # The bot committed the new project into projects.yaml.
+        reg = fake.files.get(("wiggleverse", "registry", "main", "projects.yaml"))
+        assert reg is not None
+        assert "id: acme" in reg["content"]
+        assert "content_repo: acme-content" in reg["content"]
+
+        # The registry refresh mirrored a projects row + its default collection.
+        prow = db.conn().execute(
+            "SELECT name, content_repo, visibility FROM projects WHERE id='acme'"
+        ).fetchone()
+        assert (prow["name"], prow["content_repo"], prow["visibility"]) == (
+            "Acme", "acme-content", "public")
+        crow = db.conn().execute(
+            "SELECT type, project_id, subfolder FROM collections WHERE id='acme'"
+        ).fetchone()
+        assert (crow["type"], crow["project_id"], crow["subfolder"]) == ("bdd", "acme", "")
+
+        # It is now visible in the deployment directory and readable.
+        ids = {p["id"] for p in client.get("/api/deployment").json()["projects"]}
+        assert "acme" in ids
+        assert client.get("/api/projects/acme").status_code == 200
+
+        # An audit row records the structural action with the global Owner actor.
+        act = db.conn().execute(
+            "SELECT actor_user_id FROM actions WHERE action_kind='create_project'"
+        ).fetchone()
+        assert act is not None and act["actor_user_id"] == 1
+
+
+def test_create_project_custom_content_repo_name(app_with_fake_gitea):
+    app, fake = app_with_fake_gitea
+    with TestClient(app) as client:
+        provision_user_row(user_id=1, login="ben", role="owner")
+        sign_in_as(client, user_id=1, gitea_login="ben", display_name="Ben",
+                   role="owner", email="ben@test")
+        r = client.post("/api/projects",
+                        json={"project_id": "beta", "name": "Beta", "type": "document",
+                              "content_repo": "beta-corpus"})
+        assert r.status_code == 200, r.text
+        assert ("wiggleverse", "beta-corpus") in fake.repos
+        prow = db.conn().execute(
+            "SELECT content_repo FROM projects WHERE id='beta'"
+        ).fetchone()
+        assert prow["content_repo"] == "beta-corpus"
+
+
+def test_create_project_requires_global_owner(app_with_fake_gitea):
+    # A plain deployment contributor is not a global Owner (C: + New project is a
+    # global-Owner action), even though they may create collections.
+    app, _ = app_with_fake_gitea
+    with TestClient(app) as client:
+        provision_user_row(user_id=2, login="alice", role="contributor")
+        sign_in_as(client, user_id=2, gitea_login="alice", display_name="Alice",
+                   role="contributor", email="alice@test")
+        r = client.post("/api/projects",
+                        json={"project_id": "x", "name": "X", "type": "bdd"})
+        assert r.status_code == 403
+
+
+def test_create_project_global_owner_grant_permitted(app_with_fake_gitea):
+    # An explicit global-scope Owner grant (not a deployment owner/admin) may
+    # create projects.
+    app, _ = app_with_fake_gitea
+    with TestClient(app) as client:
+        provision_user_row(user_id=3, login="gina", role="contributor")
+        db.conn().execute(
+            "INSERT INTO memberships (scope_type, scope_id, user_id, role) "
+            "VALUES ('global', '*', 3, 'owner')"
+        )
+        sign_in_as(client, user_id=3, gitea_login="gina", display_name="Gina",
+                   role="contributor", email="gina@test")
+        r = client.post("/api/projects",
+                        json={"project_id": "gproj", "name": "G", "type": "document"})
+        assert r.status_code == 200, r.text
+
+
+def test_create_project_anonymous_rejected(app_with_fake_gitea):
+    app, _ = app_with_fake_gitea
+    with TestClient(app) as client:
+        r = client.post("/api/projects",
+                        json={"project_id": "x", "name": "X", "type": "bdd"})
+        assert r.status_code in (401, 403)
+
+
+def test_create_project_rejects_duplicate(app_with_fake_gitea):
+    app, _ = app_with_fake_gitea
+    with TestClient(app) as client:
+        provision_user_row(user_id=1, login="ben", role="owner")
+        sign_in_as(client, user_id=1, gitea_login="ben", display_name="Ben",
+                   role="owner", email="ben@test")
+        ok = client.post("/api/projects",
+                         json={"project_id": "acme", "name": "Acme", "type": "bdd"})
+        assert ok.status_code == 200, ok.text
+        dup = client.post("/api/projects",
+                          json={"project_id": "acme", "name": "Acme 2", "type": "bdd"})
+        assert dup.status_code == 409
+
+
+def test_create_project_rejects_reserved_default_id(app_with_fake_gitea):
+    app, _ = app_with_fake_gitea
+    with TestClient(app) as client:
+        provision_user_row(user_id=1, login="ben", role="owner")
+        sign_in_as(client, user_id=1, gitea_login="ben", display_name="Ben",
+                   role="owner", email="ben@test")
+        r = client.post("/api/projects",
+                        json={"project_id": "default", "name": "X", "type": "bdd"})
+        assert r.status_code == 422
+
+
+def test_create_project_rejects_bad_type(app_with_fake_gitea):
+    app, _ = app_with_fake_gitea
+    with TestClient(app) as client:
+        provision_user_row(user_id=1, login="ben", role="owner")
+        sign_in_as(client, user_id=1, gitea_login="ben", display_name="Ben",
+                   role="owner", email="ben@test")
+        r = client.post("/api/projects",
+                        json={"project_id": "x", "name": "X", "type": "nonsense"})
+        assert r.status_code == 422
+
+
+# --- C3.1 / C3.2: deployment-directory empty-state signals ------------------
+
+
+def test_deployment_owner_sees_create_project_capability(app_with_fake_gitea):
+    # C3.1: a global Owner is offered the create-project action.
+    app, _ = app_with_fake_gitea
+    with TestClient(app) as client:
+        provision_user_row(user_id=1, login="ben", role="owner")
+        sign_in_as(client, user_id=1, gitea_login="ben", display_name="Ben", role="owner")
+        body = client.get("/api/deployment").json()
+        assert body["viewer"]["can_create_project"] is True
+
+
+def test_deployment_non_owner_no_create_capability(app_with_fake_gitea):
+    # C3.2: a granted account with no roles is not offered create-project.
+    app, _ = app_with_fake_gitea
+    with TestClient(app) as client:
+        provision_user_row(user_id=2, login="vee", role="contributor")
+        sign_in_as(client, user_id=2, gitea_login="vee", display_name="Vee", role="contributor")
+        body = client.get("/api/deployment").json()
+        assert body["viewer"]["can_create_project"] is False
+
+
+def test_deployment_default_readable_when_default_is_public(app_with_fake_gitea):
+    # The seeded default project is public → readable → the N=1 redirect target
+    # is valid (land-in-corpus preserved).
+    app, _ = app_with_fake_gitea
+    with TestClient(app) as client:
+        body = client.get("/api/deployment").json()
+        assert body["default_project_readable"] is True
+
+
+def test_deployment_default_not_readable_when_only_gated(app_with_fake_gitea):
+    # C3.2: the only project is gated; a granted non-member sees no visible
+    # projects AND default_project_readable False → the frontend renders the
+    # empty directory (no 404 bounce).
+    app, _ = app_with_fake_gitea
+    with TestClient(app) as client:
+        db.conn().execute("UPDATE projects SET visibility='gated' WHERE id='default'")
+        db.conn().execute("UPDATE collections SET visibility='gated' WHERE id='default'")
+        provision_user_row(user_id=2, login="vee", role="contributor")
+        sign_in_as(client, user_id=2, gitea_login="vee", display_name="Vee", role="contributor")
+        body = client.get("/api/deployment").json()
+        assert body["projects"] == []
+        assert body["default_project_readable"] is False

backend/tests/test_docs_sessions_vertical.py

@@ -70,27 +70,32 @@ class _UpstreamHandler:
 
 
 @pytest.fixture
-def patched_httpx(monkeypatch):
+def patched_httpx(monkeypatch, app_with_fake_gitea):  # noqa: F811
     """Provide a hook the test can call to install a MockTransport.
 
-    Returns a closure: `install(handler)` patches
-    `app.docs_sessions.httpx.AsyncClient` so every constructed client
-    uses the handler's transport.
+    Returns a closure: `install(handler)` patches `httpx.AsyncClient`
+    (via `app.docs_sessions.httpx.AsyncClient`) so every constructed
+    client uses the handler's transport.
 
-    NB: the upstream `app_with_fake_gitea` fixture also patches
-    `httpx.AsyncClient` (to route gitea calls to a FakeGitea handler),
-    and because `httpx` is a single shared module, that patch mutates
-    the *same* `AsyncClient` attribute we're about to overwrite. We
-    therefore import the unpatched class directly from the
-    `httpx._client` module so our install path can construct a fresh
-    real client around our MockTransport without going through the
-    FakeGitea wrapper.
+    M3 note: lifespan now calls `refresh_registry` which hits FakeGitea
+    via the gitea transport. Since `httpx` is a module singleton, installing
+    the docs transport would clobber the FakeGitea mock already installed
+    by `app_with_fake_gitea`. We use a COMPOSITE handler: Gitea API
+    requests (to `http://gitea.test/`) are delegated to FakeGitea; all
+    other requests go to the test-specific handler.
     """
     from httpx._client import AsyncClient as RealAsyncClient
 
+    _fake = app_with_fake_gitea[1]
+
     def install(handler):
+        def composite(request: httpx.Request) -> httpx.Response:
+            if "gitea.test" in str(request.url):
+                return _fake.handle(request)
+            return handler(request)
+
         def patched(*args, **kwargs):
-            kwargs["transport"] = httpx.MockTransport(handler)
+            kwargs["transport"] = httpx.MockTransport(composite)
             return RealAsyncClient(*args, **kwargs)
 
         monkeypatch.setattr("app.docs_sessions.httpx.AsyncClient", patched)

backend/tests/test_docs_specs_vertical.py

@@ -79,19 +79,28 @@ class _UpstreamHandler:
 
 
 @pytest.fixture
-def patched_httpx(monkeypatch):
+def patched_httpx(monkeypatch, app_with_fake_gitea):  # noqa: F811
     """Provide a hook the test can call to install a MockTransport.
 
-    Same shape as the docs_sessions fixture — `app_with_fake_gitea`
-    monkeypatches `httpx.AsyncClient` for the gitea side, so we
-    construct from the unpatched class directly to avoid the
-    FakeGitea wrapper.
+    M3 note: lifespan now calls `refresh_registry` which hits FakeGitea
+    via the gitea transport. Since `httpx` is a module singleton, installing
+    the docs transport would clobber the FakeGitea mock already installed
+    by `app_with_fake_gitea`. We use a COMPOSITE handler: Gitea API
+    requests (to `http://gitea.test/`) are delegated to FakeGitea; all
+    other requests go to the test-specific handler.
     """
     from httpx._client import AsyncClient as RealAsyncClient
 
+    _fake = app_with_fake_gitea[1]
+
     def install(handler):
+        def composite(request: httpx.Request) -> httpx.Response:
+            if "gitea.test" in str(request.url):
+                return _fake.handle(request)
+            return handler(request)
+
         def patched(*args, **kwargs):
-            kwargs["transport"] = httpx.MockTransport(handler)
+            kwargs["transport"] = httpx.MockTransport(composite)
             return RealAsyncClient(*args, **kwargs)
 
         monkeypatch.setattr("app.docs_specs.httpx.AsyncClient", patched)

backend/tests/test_e2e_smoke.py

@@ -119,19 +119,20 @@ def test_full_user_lifecycle_propose_through_hygiene(app_with_fake_gitea):
         r = client.post(f"/api/rfcs/ohm/prs/{body_pr}/merge")
         assert r.status_code == 200, r.text
 
-        # --- 7. Graduate the super-draft. ---
+        # --- 7. Graduate the super-draft (in-place flip, §13). ---
         r = client.post(
             "/api/rfcs/ohm/graduate?_sync=1",
-            json={"rfc_id": "RFC-0001", "repo_name": "rfc-0001-ohm",
-                  "owners": ["ben"]},
+            json={"rfc_id": "RFC-0001", "owners": ["ben"]},
         )
         assert r.status_code == 200, r.text
         assert r.json()["succeeded"] is True
         d = client.get("/api/rfcs/ohm").json()
         assert d["state"] == "active"
-        assert d["repo"] == "wiggleverse/rfc-0001-ohm"
+        # Meta-only topology (§1): no per-RFC repo — the active RFC lives
+        # in its meta entry, `repo` stays null.
+        assert d["repo"] is None
 
-        # --- 8. Alice opens a PR on the now-active RFC's per-RFC repo. ---
+        # --- 8. Alice opens a PR on the now-active RFC (meta repo). ---
         # v0.16.0 (item #12): ben is the RFC owner now; alice needs a
         # per-RFC contributor invitation to cut a branch. In the
         # production flow, ben would invite her via /invitations and
@@ -200,8 +201,8 @@ def test_full_user_lifecycle_propose_through_hygiene(app_with_fake_gitea):
         )
         assert counters["deleted_post_merge"] >= 1, counters
 
-        # The branch is gone from FakeGitea + cached row flipped.
-        assert active_branch not in fake.branches[("wiggleverse", "rfc-0001-ohm")]
+        # The branch is gone from FakeGitea (meta repo) + cached row flipped.
+        assert active_branch not in fake.branches[("wiggleverse", "meta")]
         cached = db.conn().execute(
             "SELECT state FROM cached_branches WHERE rfc_slug = 'ohm' AND branch_name = ?",
             (active_branch,),

backend/tests/test_email_envelope.py

@@ -11,6 +11,8 @@ from __future__ import annotations
 
 from email.utils import parsedate_to_datetime
 
+import pytest
+
 from app.email_envelope import build_envelope
 
 
@@ -160,14 +162,18 @@ def test_envelope_plain_only_body_is_text_plain():
     assert msg.get_content().strip() == "Hello, world."
 
 
-def test_envelope_with_html_is_multipart_alternative():
-    msg = build_envelope(**_base_kwargs(body_html="<p>Hello, <b>world</b>.</p>"))
-    assert msg.get_content_type() == "multipart/alternative"
-    # Two parts: text/plain first (so plain-text clients picking the
-    # first part get the readable text), text/html second.
-    parts = list(msg.iter_parts())
-    assert len(parts) == 2
-    assert parts[0].get_content_type() == "text/plain"
-    assert parts[1].get_content_type() == "text/html"
-    assert "Hello, world." in parts[0].get_content()
-    assert "<b>world</b>" in parts[1].get_content()
+def test_envelope_html_body_is_guarded_not_enabled():
+    # I3 (security-audit-0026): the HTML/multipart-alternative path is
+    # intentionally not enabled — passing body_html must fail loudly so
+    # a future caller can't silently ship unescaped user HTML (the C1
+    # stored-XSS class in the mail channel). When HTML mail is enabled
+    # deliberately, this test flips to assert the multipart shape.
+    with pytest.raises(NotImplementedError):
+        build_envelope(**_base_kwargs(body_html="<p>Hello, <b>world</b>.</p>"))
+
+
+def test_envelope_html_none_is_plain_only():
+    # The guard keys on `is not None`, so the default (None) stays the
+    # live plain-text path — exercised here to lock the boundary.
+    msg = build_envelope(**_base_kwargs(body_html=None))
+    assert msg.get_content_type() == "text/plain"

backend/tests/test_entry_review_fields.py

@@ -0,0 +1,42 @@
+"""§22.4c — the unreviewed/reviewed_at/reviewed_by entry frontmatter fields."""
+from __future__ import annotations
+
+from app import entry as entry_mod
+
+
+def test_parse_defaults_unreviewed_false_when_absent():
+    text = "---\nslug: ohm\ntitle: OHM\nstate: active\n---\n\nBody.\n"
+    e = entry_mod.parse(text)
+    assert e.unreviewed is False
+    assert e.reviewed_at is None
+    assert e.reviewed_by is None
+
+
+def test_parse_reads_review_fields():
+    text = (
+        "---\nslug: ohm\ntitle: OHM\nstate: active\n"
+        "unreviewed: true\nreviewed_at: '2026-06-03'\nreviewed_by: ben\n---\n\nBody.\n"
+    )
+    e = entry_mod.parse(text)
+    assert e.unreviewed is True
+    assert e.reviewed_at == "2026-06-03"
+    assert e.reviewed_by == "ben"
+
+
+def test_serialize_emits_review_fields_only_when_meaningful():
+    e = entry_mod.Entry(slug="a", title="A", state="super-draft")
+    assert "unreviewed" not in entry_mod.serialize(e)
+    assert "reviewed_at" not in entry_mod.serialize(e)
+    e2 = entry_mod.Entry(slug="b", title="B", state="active", unreviewed=True)
+    assert "unreviewed: true" in entry_mod.serialize(e2)
+
+
+def test_round_trip_preserves_review_fields():
+    e = entry_mod.Entry(
+        slug="b", title="B", state="active",
+        unreviewed=False, reviewed_at="2026-06-03", reviewed_by="ben",
+    )
+    back = entry_mod.parse(entry_mod.serialize(e))
+    assert back.reviewed_at == "2026-06-03"
+    assert back.reviewed_by == "ben"
+    assert back.unreviewed is False

backend/tests/test_graduation_vertical.py

@@ -1,29 +1,29 @@
-"""End-to-end integration tests for the Slice 5 vertical (§13 in full).
+"""End-to-end integration tests for the §13 graduation flow under the
+meta-only topology (SPEC §1, ROADMAP #36).
 
-Walks the §13.3 transactional sequence end-to-end against the in-process
-FakeGitea from test_propose_vertical.py:
+Graduation is an in-place state flip on the meta entry — no per-RFC repo
+is created, the body is kept, and there is no multi-step transaction or
+rollback (§13.3). These tests walk it against the in-process FakeGitea
+from test_propose_vertical.py:
 
-  * Seed an owned super-draft (skipping the propose+merge + §13.1 claim
-    round-trips already proven by Slice 1 and exercised in
-    test_claim_opens_meta_pr below for the §13.1 surface itself).
+  * Seed an owned super-draft (the §13.1 claim flow is exercised
+    separately in test_claim_opens_meta_pr).
   * GET /api/rfcs/<slug>/graduate/check returns per-field validity for
-    the dialog.
-  * GET /api/rfcs/<slug>/blocking-prs returns the §9.8 precondition list.
-  * POST /api/rfcs/<slug>/graduate?_sync=1 runs the five-step sequence
-    inline. On success: per-RFC repo exists with RFC.md / README.md /
-    .rfc/metadata.yaml, meta-entry body is stripped, frontmatter is
-    graduated, cached_rfcs.state is 'active'.
-  * §9.8 precondition gate refuses the start when a body-edit PR is open.
-  * Rollback on a mid-sequence failure unwinds repo creation cleanly.
-  * §13.4 chat migration: whole-doc threads under (slug, 'main') survive
-    graduation unchanged — the rfc_slug is the canonical key per §2.3,
-    so no data movement is needed.
-  * §9.8 pre-graduation history: the new RFC's /main response surfaces
-    edit-branch threads under `pre_graduation_history`.
+    the two-field dialog (integer id + owners; no repo name).
+  * POST /api/rfcs/<slug>/graduate?_sync=1 opens + merges the flip PR
+    inline. On success: NO per-RFC repo, the meta entry is `state:
+    active` with the body KEPT and `repo` null, cached_rfcs.state flips
+    to 'active'.
+  * An open body-edit PR no longer blocks graduation (§9.8) — they
+    coexist.
+  * An open-PR failure leaves the entry a super-draft (nothing created);
+    a merge failure cleans up the half-open PR/branch and leaves the
+    entry a super-draft.
+  * §13.4: chat threads + edit branches stay put — the slug is the
+    canonical key per §2.3, so nothing moves at the flip.
 
-The orchestrator's `?_sync=1` seam awaits the sequence inline so the
-test can assert post-conditions on the same event loop tick. Production
-clients use the spec-described SSE shape via `/graduate/progress`.
+The orchestrator's `?_sync=1` seam awaits the flip inline so the test can
+assert post-conditions on the same event loop tick.
 """
 from __future__ import annotations
 
@@ -110,7 +110,9 @@ def seed_owned_super_draft(fake: FakeGitea, *, slug: str, title: str, pitch: str
 # ---------------------------------------------------------------------------
 
 
-def test_graduate_check_validates_three_fields(app_with_fake_gitea):
+def test_graduate_check_validates_id_and_owners(app_with_fake_gitea):
+    """Two-field dialog under meta-only: integer id + owners. No repo
+    name to validate (§13.2)."""
     from fastapi.testclient import TestClient
 
     app, fake = app_with_fake_gitea
@@ -121,57 +123,46 @@ def test_graduate_check_validates_three_fields(app_with_fake_gitea):
         sign_in_as(client, user_id=1, gitea_login="ben",
                    display_name="Ben", role="owner")
 
-        # Happy: a fresh RFC-0001 + rfc-0001-ohm repo name.
-        r = client.get("/api/rfcs/ohm/graduate/check",
-                       params={"id": "RFC-0001", "repo": "rfc-0001-ohm"})
+        # Happy: a fresh RFC-0001.
+        r = client.get("/api/rfcs/ohm/graduate/check", params={"id": "RFC-0001"})
         assert r.status_code == 200, r.text
         d = r.json()
         assert d["id"]["ok"] is True
-        assert d["repo"]["ok"] is True
         assert d["owners"]["ok"] is True
-        assert d["blocking_prs"]["ok"] is True
         assert d["can_submit"] is True
+        # No repo field in the meta-only check response.
+        assert "repo" not in d
 
         # ID format error — non-numeric tail.
-        r = client.get("/api/rfcs/ohm/graduate/check",
-                       params={"id": "RFC-abcd", "repo": "rfc-0001-ohm"})
+        r = client.get("/api/rfcs/ohm/graduate/check", params={"id": "RFC-abcd"})
         d = r.json()
         assert d["id"]["ok"] is False
         assert d["can_submit"] is False
 
-        # Repo name pattern error — leading dot.
-        r = client.get("/api/rfcs/ohm/graduate/check",
-                       params={"id": "RFC-0001", "repo": ".bad"})
-        d = r.json()
-        assert d["repo"]["ok"] is False
-
 
 def test_graduate_check_refuses_when_no_owners(app_with_fake_gitea):
     """An unclaimed super-draft fails the owners precondition; can_submit
-    flips false even with valid id+repo."""
+    flips false even with a valid id."""
     from fastapi.testclient import TestClient
 
     app, fake = app_with_fake_gitea
     with TestClient(app) as client:
         provision_user_row(user_id=1, login="ben", role="owner")
-        # No owners — simulates an unclaimed super-draft.
         seed_owned_super_draft(fake, slug="ohm", title="OHM", pitch=PITCH, owners=[])
         sign_in_as(client, user_id=1, gitea_login="ben",
                    display_name="Ben", role="owner")
-        r = client.get("/api/rfcs/ohm/graduate/check",
-                       params={"id": "RFC-0001", "repo": "rfc-0001-ohm"})
+        r = client.get("/api/rfcs/ohm/graduate/check", params={"id": "RFC-0001"})
         d = r.json()
         assert d["owners"]["ok"] is False
         assert "No owners" in d["owners"]["error"]
         assert d["can_submit"] is False
 
 
-def test_graduate_happy_path_runs_five_steps_and_flips_state(app_with_fake_gitea):
-    """The full §13.3 sequence: create repo, seed files, open PR, merge
-    PR, refresh cache. End state: cached_rfcs.state='active', the meta
-    entry's body is stripped, the per-RFC repo has RFC.md, the audit
-    log carries graduate_start → graduate_complete bracketing the
-    per-step rows."""
+def test_graduate_happy_path_flips_in_place_keeping_body(app_with_fake_gitea):
+    """The meta-only flip: open + merge a frontmatter PR. End state:
+    cached_rfcs.state='active', the meta entry's body is KEPT, `repo` is
+    null, NO per-RFC repo exists, and the audit log carries graduate_start
+    → graduate_pr_open → graduate_pr_merge → graduate_complete."""
     from fastapi.testclient import TestClient
     from app import db, entry as entry_mod
 
@@ -186,60 +177,57 @@ def test_graduate_happy_path_runs_five_steps_and_flips_state(app_with_fake_gitea
 
         r = client.post(
             "/api/rfcs/ohm/graduate?_sync=1",
-            json={"rfc_id": "RFC-0042", "repo_name": "rfc-0042-ohm",
-                  "owners": ["ben"]},
+            json={"rfc_id": "RFC-0042", "owners": ["ben"]},
         )
         assert r.status_code == 200, r.text
         d = r.json()
         assert d["finished"] is True
         assert d["succeeded"] is True
-        assert d["repo"] == "wiggleverse/rfc-0042-ohm"
+        # No repo in the response, no per-RFC repo on Gitea.
+        assert "repo" not in d
+        assert ("wiggleverse", "rfc-0042-ohm") not in fake.repos
+        assert not any(
+            k[1].startswith("rfc-0042") for k in fake.repos
+        ), f"a per-RFC repo was created: {fake.repos}"
 
-        # 1. Per-RFC repo exists on Gitea.
-        assert ("wiggleverse", "rfc-0042-ohm") in fake.repos
-        # 2. Seed files landed on main.
-        assert ("wiggleverse", "rfc-0042-ohm", "main", "RFC.md") in fake.files
-        assert ("wiggleverse", "rfc-0042-ohm", "main", "README.md") in fake.files
-        assert ("wiggleverse", "rfc-0042-ohm", "main", ".rfc/metadata.yaml") in fake.files
-        rfc_md = fake.files[("wiggleverse", "rfc-0042-ohm", "main", "RFC.md")]["content"]
-        assert "Open Human Model is a framework" in rfc_md
-        # 3. Meta entry body is stripped + frontmatter graduated.
+        # Meta entry on main: state flipped, body KEPT, repo null.
         meta_text = fake.files[("wiggleverse", "meta", "main", "rfcs/ohm.md")]["content"]
         graduated = entry_mod.parse(meta_text)
         assert graduated.state == "active"
         assert graduated.id == "RFC-0042"
-        assert graduated.repo == "wiggleverse/rfc-0042-ohm"
+        assert graduated.repo is None
         assert graduated.graduated_by == "ben"
         assert graduated.graduated_at  # non-empty ISO date
-        assert graduated.body.strip() == ""
-        # 5. cached_rfcs.state flipped to active via the inline refresh.
+        assert "Open Human Model is a framework" in graduated.body
+
+        # cached_rfcs flipped to active via the inline refresh; body intact.
         cached = db.conn().execute(
             "SELECT state, rfc_id, repo, body FROM cached_rfcs WHERE slug = 'ohm'"
         ).fetchone()
         assert cached["state"] == "active"
         assert cached["rfc_id"] == "RFC-0042"
-        assert cached["repo"] == "wiggleverse/rfc-0042-ohm"
-        # cached body now mirrors RFC.md from the per-RFC repo.
+        assert cached["repo"] is None
         assert "Open Human Model is a framework" in cached["body"]
 
-        # Audit log: graduate_start, graduate_repo_create, graduate_repo_seed,
-        # graduate_pr_open, graduate_pr_merge, graduate_complete, in order.
         kinds = [
-            r["action_kind"]
-            for r in db.conn().execute(
+            row["action_kind"]
+            for row in db.conn().execute(
                 "SELECT action_kind FROM actions WHERE rfc_slug = 'ohm' ORDER BY id"
             )
         ]
-        for needed in ("graduate_start", "graduate_repo_create",
-                       "graduate_repo_seed", "graduate_pr_open",
+        for needed in ("graduate_start", "graduate_pr_open",
                        "graduate_pr_merge", "graduate_complete"):
             assert needed in kinds, f"missing audit row {needed}: {kinds}"
+        # The retired per-repo steps must NOT appear.
+        for gone in ("graduate_repo_create", "graduate_repo_seed",
+                     "graduate_repo_delete", "graduate_rollback"):
+            assert gone not in kinds, f"retired audit row present: {gone}"
 
 
-def test_graduate_refuses_when_body_edit_pr_open(app_with_fake_gitea):
-    """§9.8: an open meta-repo body-edit PR against rfcs/<slug>.md blocks
-    graduation before the bot starts the sequence — §13.3's rollback
-    complexity does not grow."""
+def test_graduate_coexists_with_open_body_edit_pr(app_with_fake_gitea):
+    """§9.8 (meta-only): an open meta-repo body-edit PR no longer blocks
+    graduation — the body is kept, so they coexist. /check stays
+    submittable and the flip succeeds."""
     from fastapi.testclient import TestClient
     from app import db
 
@@ -249,13 +237,11 @@ def test_graduate_refuses_when_body_edit_pr_open(app_with_fake_gitea):
         provision_user_row(user_id=2, login="alice", role="contributor")
         seed_owned_super_draft(fake, slug="ohm", title="OHM",
                                pitch=PITCH, owners=["ben"])
-        # v0.16.0 (item #12): ben is the RFC owner; alice needs a per-RFC
-        # contributor invitation to cut an edit branch on the super-draft.
         grant_rfc_collaborator(user_id=2, rfc_slug="ohm", role_in_rfc="contributor")
         sign_in_as(client, user_id=2, gitea_login="alice",
                    display_name="Alice", role="contributor")
 
-        # Cut an edit branch and open a body-edit PR (full Slice 4 path).
+        # Cut an edit branch and open a body-edit PR.
         branch = client.post("/api/rfcs/ohm/start-edit-branch", json={}).json()["branch_name"]
         view = client.get(f"/api/rfcs/ohm/branches/{branch}").json()
         thread_id = view["main_thread_id"]
@@ -279,94 +265,31 @@ def test_graduate_refuses_when_body_edit_pr_open(app_with_fake_gitea):
             f"/api/rfcs/ohm/branches/{branch}/open-pr",
             json={"title": "Add harm", "description": "Adds harm dimension."},
         ).json()["pr_number"]
+        assert pr_number  # PR is open
 
-        # /blocking-prs surfaces it.
+        # /check stays submittable despite the open body-edit PR.
         sign_in_as(client, user_id=1, gitea_login="ben",
                    display_name="Ben", role="owner")
-        r = client.get("/api/rfcs/ohm/blocking-prs")
-        items = r.json()["items"]
-        assert len(items) == 1
-        assert items[0]["pr_number"] == pr_number
+        d = client.get("/api/rfcs/ohm/graduate/check", params={"id": "RFC-0001"}).json()
+        assert "blocking_prs" not in d
+        assert d["can_submit"] is True
 
-        # /check refuses can_submit.
-        r = client.get("/api/rfcs/ohm/graduate/check",
-                       params={"id": "RFC-0001", "repo": "rfc-0001-ohm"})
-        d = r.json()
-        assert d["blocking_prs"]["ok"] is False
-        assert d["can_submit"] is False
-
-        # POST refuses with 409 — the bot never starts the sequence.
+        # The flip succeeds — coexists with the open body-edit PR.
         r = client.post(
             "/api/rfcs/ohm/graduate?_sync=1",
-            json={"rfc_id": "RFC-0001", "repo_name": "rfc-0001-ohm",
-                  "owners": ["ben"]},
+            json={"rfc_id": "RFC-0001", "owners": ["ben"]},
         )
-        assert r.status_code == 409
-        assert "blocking graduation" in r.text or "block" in r.text
-
-
-def test_graduate_rollback_on_step_2_seed_failure(app_with_fake_gitea):
-    """Step 2 (seed files) fails partway → the orchestrator rolls back
-    step 1 (delete the repo) and records the rollback in the audit log.
-    The cached_rfcs row stays at 'super-draft'."""
-    from fastapi.testclient import TestClient
-    from app import db
-    from app.bot import Bot
-    from app.gitea import Gitea, GiteaError
-
-    app, fake = app_with_fake_gitea
-    with TestClient(app) as client:
-        provision_user_row(user_id=1, login="ben", role="owner")
-        seed_owned_super_draft(fake, slug="ohm", title="OHM",
-                               pitch=PITCH, owners=["ben"])
-        sign_in_as(client, user_id=1, gitea_login="ben",
-                   display_name="Ben", role="owner")
-
-        # Monkey-patch the bot to fail on seed_graduated_rfc. The repo
-        # has already been created in step 1; the rollback must delete it.
-        orig_seed = Bot.seed_graduated_rfc
-        async def boom(self, *args, **kwargs):
-            raise GiteaError(500, "simulated seed failure for rollback test")
-        Bot.seed_graduated_rfc = boom
-        try:
-            r = client.post(
-                "/api/rfcs/ohm/graduate?_sync=1",
-                json={"rfc_id": "RFC-0003", "repo_name": "rfc-0003-ohm",
-                      "owners": ["ben"]},
-            )
-        finally:
-            Bot.seed_graduated_rfc = orig_seed
         assert r.status_code == 200, r.text
-        d = r.json()
-        assert d["finished"] is True
-        assert d["succeeded"] is False
-
-        # Repo deleted as the rollback inverse.
-        assert ("wiggleverse", "rfc-0003-ohm") not in fake.repos
-        # Meta entry unchanged.
+        assert r.json()["succeeded"] is True
         cached = db.conn().execute(
-            "SELECT state, rfc_id FROM cached_rfcs WHERE slug = 'ohm'"
+            "SELECT state FROM cached_rfcs WHERE slug = 'ohm'"
         ).fetchone()
-        assert cached["state"] == "super-draft"
-        assert cached["rfc_id"] is None
-        # Audit log carries the rollback row.
-        kinds = [
-            r["action_kind"]
-            for r in db.conn().execute(
-                "SELECT action_kind FROM actions WHERE rfc_slug = 'ohm' ORDER BY id"
-            )
-        ]
-        assert "graduate_start" in kinds
-        assert "graduate_repo_create" in kinds
-        assert "graduate_repo_delete" in kinds
-        assert "graduate_rollback" in kinds
-        assert "graduate_complete" not in kinds
+        assert cached["state"] == "active"
 
 
-def test_graduate_rollback_on_step_3_pr_open_failure(app_with_fake_gitea):
-    """Step 3 (open PR) fails → the orchestrator rolls back steps 2 and
-    1 (deleting the repo, which reclaims the seed commits at the same
-    time). The meta-repo entry is untouched."""
+def test_graduate_open_pr_failure_leaves_super_draft(app_with_fake_gitea):
+    """An open-PR failure creates nothing — the entry stays a super-draft
+    with its body intact and no graduation PR on the meta repo."""
     from fastapi.testclient import TestClient
     from app import db
     from app.bot import Bot
@@ -387,19 +310,92 @@ def test_graduate_rollback_on_step_3_pr_open_failure(app_with_fake_gitea):
         try:
             r = client.post(
                 "/api/rfcs/ohm/graduate?_sync=1",
-                json={"rfc_id": "RFC-0007", "repo_name": "rfc-0007-ohm",
-                      "owners": ["ben"]},
+                json={"rfc_id": "RFC-0007", "owners": ["ben"]},
             )
         finally:
             Bot.open_graduation_pr = orig_open_pr
         assert r.status_code == 200, r.text
         assert r.json()["succeeded"] is False
-        # Repo torn down.
-        assert ("wiggleverse", "rfc-0007-ohm") not in fake.repos
-        # Meta entry's body still has the pitch (not stripped).
+
+        # Entry untouched: still super-draft, body intact on main.
+        cached = db.conn().execute(
+            "SELECT state, rfc_id FROM cached_rfcs WHERE slug = 'ohm'"
+        ).fetchone()
+        assert cached["state"] == "super-draft"
+        assert cached["rfc_id"] is None
         meta_text = fake.files[("wiggleverse", "meta", "main", "rfcs/ohm.md")]["content"]
         assert "Open Human Model is a framework" in meta_text
 
+        kinds = [
+            row["action_kind"]
+            for row in db.conn().execute(
+                "SELECT action_kind FROM actions WHERE rfc_slug = 'ohm' ORDER BY id"
+            )
+        ]
+        assert "graduate_start" in kinds
+        assert "graduate_failed" in kinds
+        assert "graduate_complete" not in kinds
+
+
+def test_graduate_merge_failure_cleans_up_pr(app_with_fake_gitea):
+    """A merge failure leaves the flip PR open on its dash-suffixed
+    branch; the orchestrator closes the PR and deletes the branch so
+    failed attempts don't accumulate. The entry stays a super-draft —
+    the flip PR's commit was on a branch, not on main."""
+    from fastapi.testclient import TestClient
+    from app import db
+    from app.bot import Bot
+    from app.gitea import GiteaError
+
+    app, fake = app_with_fake_gitea
+    with TestClient(app) as client:
+        provision_user_row(user_id=1, login="ben", role="owner")
+        seed_owned_super_draft(fake, slug="ohm", title="OHM",
+                               pitch=PITCH, owners=["ben"])
+        sign_in_as(client, user_id=1, gitea_login="ben",
+                   display_name="Ben", role="owner")
+
+        orig_merge = Bot.merge_graduation_pr
+        async def boom(self, *args, **kwargs):
+            raise GiteaError(502, "simulated merge failure")
+        Bot.merge_graduation_pr = boom
+        try:
+            r = client.post(
+                "/api/rfcs/ohm/graduate?_sync=1",
+                json={"rfc_id": "RFC-0009", "owners": ["ben"]},
+            )
+        finally:
+            Bot.merge_graduation_pr = orig_merge
+        assert r.status_code == 200, r.text
+        assert r.json()["succeeded"] is False
+
+        # Entry stays super-draft on main (the flip never merged).
+        cached = db.conn().execute(
+            "SELECT state FROM cached_rfcs WHERE slug = 'ohm'"
+        ).fetchone()
+        assert cached["state"] == "super-draft"
+        meta_text = fake.files[("wiggleverse", "meta", "main", "rfcs/ohm.md")]["content"]
+        assert "state: super-draft" in meta_text
+
+        # The dash-suffixed graduation branch was cleaned up.
+        grad_branches = [
+            name for (o, repo), branches in fake.branches.items()
+            if (o, repo) == ("wiggleverse", "meta")
+            for name in branches
+            if name.startswith("graduate-ohm-")
+        ]
+        assert grad_branches == [], f"leftover graduation branch: {grad_branches}"
+
+        kinds = [
+            row["action_kind"]
+            for row in db.conn().execute(
+                "SELECT action_kind FROM actions WHERE rfc_slug = 'ohm' ORDER BY id"
+            )
+        ]
+        assert "graduate_pr_open" in kinds
+        assert "graduate_failed" in kinds
+        assert "graduate_complete" not in kinds
+
 
 def test_graduate_refuses_concurrent_graduation(app_with_fake_gitea):
     """A second graduation request for a slug already in-flight is refused."""
@@ -414,17 +410,14 @@ def test_graduate_refuses_concurrent_graduation(app_with_fake_gitea):
         sign_in_as(client, user_id=1, gitea_login="ben",
                    display_name="Ben", role="owner")
 
-        # Seed a synthetic in-flight state so the registry refuses the second.
         st = api_graduation._new_active(
-            "ohm", rfc_id="RFC-0001", repo_name="rfc-0001-ohm",
-            repo_full="wiggleverse/rfc-0001-ohm", owners=["ben"], arbiters=["ben"],
+            "ohm", rfc_id="RFC-0001", owners=["ben"], arbiters=["ben"],
         )
         st.finished = False
         try:
             r = client.post(
                 "/api/rfcs/ohm/graduate?_sync=1",
-                json={"rfc_id": "RFC-0001", "repo_name": "rfc-0001-ohm",
-                      "owners": ["ben"]},
+                json={"rfc_id": "RFC-0001", "owners": ["ben"]},
             )
             assert r.status_code == 409
         finally:
@@ -432,11 +425,9 @@ def test_graduate_refuses_concurrent_graduation(app_with_fake_gitea):
 
 
 def test_chat_threads_survive_graduation_without_data_movement(app_with_fake_gitea):
-    """§13.4: chat threads on the super-draft's canonical-body view
-    (`branch_name='main'`) are interpreted as the new RFC's main-thread
-    after graduation. The rows don't move — the rfc_slug is canonical
-    per §2.3 — so the same thread surfaces from both before and after
-    the graduation."""
+    """§13.4: chat threads on the entry's main view (`branch_name='main'`)
+    stay put across the flip — the rfc_slug is canonical per §2.3 — so the
+    same thread surfaces from /branches/main before and after graduation."""
     from fastapi.testclient import TestClient
     from app import db
 
@@ -448,9 +439,6 @@ def test_chat_threads_survive_graduation_without_data_movement(app_with_fake_git
         sign_in_as(client, user_id=1, gitea_login="ben",
                    display_name="Ben", role="owner")
 
-        # Materialize a whole-doc main thread + a message on it. This
-        # mirrors what reading the canonical-body view would create
-        # lazily (§8.12 / api_branches._ensure_branch_chat_thread).
         cur = db.conn().execute(
             """
             INSERT INTO threads (rfc_slug, branch_name, anchor_kind, thread_kind, created_by)
@@ -466,32 +454,26 @@ def test_chat_threads_survive_graduation_without_data_movement(app_with_fake_git
             (thread_id,),
         )
 
-        # Graduate.
         r = client.post(
             "/api/rfcs/ohm/graduate?_sync=1",
-            json={"rfc_id": "RFC-0099", "repo_name": "rfc-0099-ohm",
-                  "owners": ["ben"]},
+            json={"rfc_id": "RFC-0099", "owners": ["ben"]},
         )
         assert r.status_code == 200, r.text
 
-        # The thread row's identity is unchanged.
         row = db.conn().execute(
             "SELECT id, branch_name FROM threads WHERE id = ?", (thread_id,),
         ).fetchone()
         assert row["branch_name"] == "main"
-        # The new RFC's main view surfaces the same thread id as its
-        # whole-doc main thread (the entry is now active, the branch
-        # 'main' now points at the per-RFC repo's main, but the
-        # `(rfc_slug, branch_name)` key remains the canonical anchor).
         r = client.get("/api/rfcs/ohm/branches/main")
         assert r.status_code == 200, r.text
         assert r.json()["main_thread_id"] == thread_id
 
 
-def test_pre_graduation_history_surfaces_edit_branch_threads(app_with_fake_gitea):
-    """§9.8: after graduation, threads on meta-repo edit branches stay
-    attached to their original branch_name and surface from the new
-    RFC's /main response under `pre_graduation_history`."""
+def test_edit_branch_surfaces_normally_after_graduation(app_with_fake_gitea):
+    """§13.4 (meta-only): after graduation an edit branch is a *current*
+    branch of the now-active RFC — it surfaces in the normal `branches`
+    list, and there is no separate `pre_graduation_history` set (that
+    affordance is legacy per-repo only)."""
     from fastapi.testclient import TestClient
     from app import db
 
@@ -501,10 +483,8 @@ def test_pre_graduation_history_surfaces_edit_branch_threads(app_with_fake_gitea
         provision_user_row(user_id=2, login="alice", role="contributor")
         seed_owned_super_draft(fake, slug="ohm", title="OHM",
                                pitch=PITCH, owners=["ben"])
-        # v0.16.0 (item #12): alice needs per-RFC contributor access.
         grant_rfc_collaborator(user_id=2, rfc_slug="ohm", role_in_rfc="contributor")
 
-        # Alice cuts an edit branch and starts chatting on it.
         sign_in_as(client, user_id=2, gitea_login="alice",
                    display_name="Alice", role="contributor")
         branch = client.post("/api/rfcs/ohm/start-edit-branch", json={}).json()["branch_name"]
@@ -513,30 +493,139 @@ def test_pre_graduation_history_surfaces_edit_branch_threads(app_with_fake_gitea
         db.conn().execute(
             """
             INSERT INTO thread_messages (thread_id, role, author_user_id, text)
-            VALUES (?, 'user', 2, 'pre-graduation note on an edit branch')
+            VALUES (?, 'user', 2, 'note on an edit branch')
             """,
             (thread_id,),
         )
 
-        # Ben graduates.
         sign_in_as(client, user_id=1, gitea_login="ben",
                    display_name="Ben", role="owner")
         r = client.post(
             "/api/rfcs/ohm/graduate?_sync=1",
-            json={"rfc_id": "RFC-0100", "repo_name": "rfc-0100-ohm",
-                  "owners": ["ben"]},
+            json={"rfc_id": "RFC-0100", "owners": ["ben"]},
         )
         assert r.status_code == 200, r.text
 
-        # /main on the now-active RFC surfaces the pre-graduation history.
-        r = client.get("/api/rfcs/ohm/main")
-        d = r.json()
+        d = client.get("/api/rfcs/ohm/main").json()
         assert d["state"] == "active"
-        hist = d["pre_graduation_history"]
-        assert len(hist) >= 1
-        assert any(h["branch_name"] == branch for h in hist)
-        target = next(h for h in hist if h["branch_name"] == branch)
-        assert target["message_count"] >= 1
+        # The edit branch is a current branch; no pre-graduation hop.
+        assert d["pre_graduation_history"] == []
+        assert any(b["name"] == branch for b in d["branches"]), \
+            f"edit branch not in branches: {[b['name'] for b in d['branches']]}"
+
+
+def test_graduate_check_accepts_blank_id(app_with_fake_gitea):
+    """§13.2 (optional number): a blank id is VALID — it means "graduate
+    without a number." `can_submit` stays true (owners are set), and an
+    absent `id` param behaves the same as an explicit empty string."""
+    from fastapi.testclient import TestClient
+
+    app, fake = app_with_fake_gitea
+    with TestClient(app) as client:
+        provision_user_row(user_id=1, login="ben", role="owner")
+        seed_owned_super_draft(fake, slug="ohm", title="OHM", pitch=PITCH, owners=["ben"])
+        sign_in_as(client, user_id=1, gitea_login="ben",
+                   display_name="Ben", role="owner")
+
+        # Explicit empty id.
+        d = client.get("/api/rfcs/ohm/graduate/check", params={"id": ""}).json()
+        assert d["id"]["ok"] is True
+        assert d["id"]["error"] is None
+        assert d["can_submit"] is True
+
+        # No id param at all — same default-accepted shape.
+        d = client.get("/api/rfcs/ohm/graduate/check").json()
+        assert d["id"]["ok"] is True
+        assert d["can_submit"] is True
+
+        # A malformed (non-blank) id is still rejected.
+        d = client.get("/api/rfcs/ohm/graduate/check", params={"id": "RFC-xx"}).json()
+        assert d["id"]["ok"] is False
+        assert d["can_submit"] is False
+
+
+def test_graduate_without_number_flips_to_active_null_id_by_slug(app_with_fake_gitea):
+    """§13.2/§13.3 (optional number): graduating with a blank id flips the
+    entry to `active` with `id: null`. The slug is the canonical identifier;
+    the catalog shows the entry as active with no number, and the audit row
+    records rfc_id null."""
+    from fastapi.testclient import TestClient
+    from app import db, entry as entry_mod
+
+    app, fake = app_with_fake_gitea
+    with TestClient(app) as client:
+        provision_user_row(user_id=1, login="ben", role="owner")
+        seed_owned_super_draft(fake, slug="ohm", title="Open Human Model",
+                               pitch=PITCH, owners=["ben"], arbiters=["ben"])
+        sign_in_as(client, user_id=1, gitea_login="ben",
+                   display_name="Ben", role="owner", email="ben@test")
+
+        # Blank rfc_id → graduate without a number.
+        r = client.post(
+            "/api/rfcs/ohm/graduate?_sync=1",
+            json={"rfc_id": "", "owners": ["ben"]},
+        )
+        assert r.status_code == 200, r.text
+        d = r.json()
+        assert d["succeeded"] is True
+        assert d["rfc_id"] is None
+
+        # Meta entry: active, id null, body kept, graduation stamped.
+        meta_text = fake.files[("wiggleverse", "meta", "main", "rfcs/ohm.md")]["content"]
+        graduated = entry_mod.parse(meta_text)
+        assert graduated.state == "active"
+        assert graduated.id is None
+        assert graduated.graduated_by == "ben"
+        assert graduated.graduated_at
+        assert "Open Human Model is a framework" in graduated.body
+
+        # Cache flipped to active with a null rfc_id.
+        cached = db.conn().execute(
+            "SELECT state, rfc_id FROM cached_rfcs WHERE slug = 'ohm'"
+        ).fetchone()
+        assert cached["state"] == "active"
+        assert cached["rfc_id"] is None
+
+        # Catalog: present as active, identified by slug (no number).
+        items = client.get("/api/rfcs").json()["items"]
+        ohm = next(i for i in items if i["slug"] == "ohm")
+        assert ohm["state"] == "active"
+        assert ohm["id"] is None
+
+        # Audit: graduate_complete with rfc_id null.
+        complete = db.conn().execute(
+            """
+            SELECT details FROM actions
+             WHERE rfc_slug = 'ohm' AND action_kind = 'graduate_complete'
+             ORDER BY id DESC LIMIT 1
+            """
+        ).fetchone()
+        assert complete is not None
+        assert _json.loads(complete["details"])["rfc_id"] is None
+
+
+def test_graduate_with_number_unchanged_when_id_absent_field(app_with_fake_gitea):
+    """Omitting the rfc_id field entirely is treated the same as blank —
+    graduates without a number — so older clients that drop the field don't
+    break, and the supplied-number path stays exactly as before."""
+    from fastapi.testclient import TestClient
+    from app import entry as entry_mod
+
+    app, fake = app_with_fake_gitea
+    with TestClient(app) as client:
+        provision_user_row(user_id=1, login="ben", role="owner")
+        seed_owned_super_draft(fake, slug="ohm", title="OHM", pitch=PITCH, owners=["ben"])
+        sign_in_as(client, user_id=1, gitea_login="ben",
+                   display_name="Ben", role="owner")
+
+        r = client.post("/api/rfcs/ohm/graduate?_sync=1", json={"owners": ["ben"]})
+        assert r.status_code == 200, r.text
+        assert r.json()["rfc_id"] is None
+        graduated = entry_mod.parse(
+            fake.files[("wiggleverse", "meta", "main", "rfcs/ohm.md")]["content"]
+        )
+        assert graduated.state == "active"
+        assert graduated.id is None
 
 
 def test_claim_opens_meta_pr(app_with_fake_gitea):
@@ -560,12 +649,10 @@ def test_claim_opens_meta_pr(app_with_fake_gitea):
         d = r.json()
         assert d["branch_name"] == "claim/ohm"
 
-        # The PR body's diff carries Alice in owners.
         text = fake.files[("wiggleverse", "meta", "claim/ohm", "rfcs/ohm.md")]["content"]
         ent = entry_mod.parse(text)
         assert "alice" in ent.owners
 
-        # cached_prs records pr_kind='meta_claim' via refresh_meta_pulls.
         row = db.conn().execute(
             "SELECT pr_kind FROM cached_prs WHERE pr_number = ?", (d["pr_number"],),
         ).fetchone()

backend/tests/test_hygiene_vertical.py

@@ -339,10 +339,10 @@ def test_hygiene_action_kinds_fire_no_notifications(app_with_fake_gitea):
 
 
 def test_graduation_rollback_deletes_dash_suffixed_branch(app_with_fake_gitea):
-    """§19.2 candidate Slice 8 settles: when graduation rolls back
-    after step 3 (open_pr), the `graduate-<slug>-<6hex>` branch is
-    deleted alongside the PR close so failed-graduation branches
-    don't accumulate on the meta repo across retries."""
+    """Meta-only (§13.3): when the flip's merge fails after the PR is
+    open, the orchestrator closes the PR and deletes its
+    `graduate-<slug>-<6hex>` branch so failed attempts don't accumulate
+    on the meta repo across retries."""
     from fastapi.testclient import TestClient
     from app import db
     from app.bot import Bot
@@ -359,24 +359,23 @@ def test_graduation_rollback_deletes_dash_suffixed_branch(app_with_fake_gitea):
         sign_in_as(client, user_id=1, gitea_login="ben",
                    display_name="Ben", role="owner")
 
-        # Force a step-4 (merge_pr) failure so step 3 (open_pr) has
-        # already landed and the rollback exercises the branch cleanup.
+        # Force a merge_pr failure so the flip PR (open_pr) has already
+        # landed and the cleanup exercises the branch deletion.
         orig_merge = Bot.merge_graduation_pr
         async def boom(self, *args, **kwargs):
-            raise GiteaError(502, "simulated merge failure for rollback test")
+            raise GiteaError(502, "simulated merge failure for cleanup test")
         Bot.merge_graduation_pr = boom
         try:
             r = client.post(
                 "/api/rfcs/ohm/graduate?_sync=1",
-                json={"rfc_id": "RFC-0099", "repo_name": "rfc-0099-ohm",
-                      "owners": ["ben"]},
+                json={"rfc_id": "RFC-0099", "owners": ["ben"]},
             )
         finally:
             Bot.merge_graduation_pr = orig_merge
         assert r.status_code == 200, r.text
         assert r.json()["succeeded"] is False
 
-        # The dash-suffixed graduation branch was deleted on rollback.
+        # The dash-suffixed graduation branch was deleted on cleanup.
         meta_branches = fake.branches[("wiggleverse", "meta")]
         graduation_branches = [n for n in meta_branches if n.startswith("graduate-ohm-")]
         assert graduation_branches == [], (

backend/tests/test_initial_state_landing.py

@@ -0,0 +1,43 @@
+"""§22.4b — a project with initial_state='active' lands new entries active +
+unreviewed; the default 'super-draft' project is unchanged."""
+from __future__ import annotations
+
+from fastapi.testclient import TestClient
+
+from test_propose_vertical import (  # noqa: F401
+    app_with_fake_gitea, tmp_env, provision_user_row, sign_in_as,
+)
+
+
+def _propose(client):
+    return client.post("/api/rfcs/propose", json={
+        "title": "Active Lander", "slug": "active-lander",
+        "pitch": "Lands active.", "tags": [],
+    })
+
+
+def test_super_draft_default_unchanged(app_with_fake_gitea):
+    from app import entry as entry_mod
+    app, fake = app_with_fake_gitea
+    with TestClient(app) as client:
+        provision_user_row(user_id=1, login="ben", role="owner")
+        sign_in_as(client, user_id=1, gitea_login="ben", display_name="Ben", role="owner")
+        assert _propose(client).status_code == 200
+        f = fake.files[("wiggleverse", "meta", "propose/active-lander", "rfcs/active-lander.md")]
+        e = entry_mod.parse(f["content"])
+        assert e.state == "super-draft"
+        assert e.unreviewed is False
+
+
+def test_active_initial_state_lands_active_unreviewed(app_with_fake_gitea):
+    from app import db, entry as entry_mod
+    app, fake = app_with_fake_gitea
+    with TestClient(app) as client:
+        db.conn().execute("UPDATE collections SET initial_state='active' WHERE project_id='default'")
+        provision_user_row(user_id=1, login="ben", role="owner")
+        sign_in_as(client, user_id=1, gitea_login="ben", display_name="Ben", role="owner")
+        assert _propose(client).status_code == 200
+        f = fake.files[("wiggleverse", "meta", "propose/active-lander", "rfcs/active-lander.md")]
+        e = entry_mod.parse(f["content"])
+        assert e.state == "active"
+        assert e.unreviewed is True

backend/tests/test_join_requests_vertical.py

@@ -0,0 +1,339 @@
+"""§22.8 S6 — request-to-join a scope + the cross-collection inbox.
+
+A user who knows a (gated) scope exists asks to join it, naming a desired role;
+the request is recorded and fanned out to that scope's Owners *across the
+subtree* (the cross-collection inbox, §22.11). An Owner accepts — which writes
+the `memberships` row via memberships.grant — or declines, and the requester is
+§15-notified either way.
+
+Built by analogy to test_contributions_vertical.py (the per-RFC contribute flow)
+and test_s4_invitations_vertical.py (the scope/membership world-builders).
+
+World: project "ohm" owns collections "model" (document, gated) and "features"
+(bdd, gated). eve is project Owner; dan is collection Owner of features only;
+zoe is a global Owner; ada is a deployment admin. ben is a plain granted account
+(no scope role) — the would-be joiner.
+"""
+from __future__ import annotations
+
+from fastapi.testclient import TestClient
+
+from app import db
+
+from test_propose_vertical import (  # noqa: F401 — fixtures land via import
+    app_with_fake_gitea,
+    provision_user_row,
+    sign_in_as,
+    tmp_env,
+)
+
+
+# ---------------------------------------------------------------------------
+# World-builders (mirror the S4 vertical)
+# ---------------------------------------------------------------------------
+
+
+def _project(pid: str, visibility: str = "gated", content_repo: str = "meta") -> None:
+    db.conn().execute(
+        "INSERT OR REPLACE INTO projects (id, name, content_repo, visibility, updated_at) "
+        "VALUES (?, ?, ?, ?, datetime('now'))",
+        (pid, pid.capitalize(), content_repo, visibility),
+    )
+
+
+def _collection(cid: str, project_id: str, *, ctype: str = "document",
+                visibility: str = "gated") -> None:
+    db.conn().execute(
+        "INSERT OR REPLACE INTO collections "
+        "(id, project_id, type, subfolder, initial_state, visibility, name, created_at, updated_at) "
+        "VALUES (?, ?, ?, ?, 'super-draft', ?, ?, datetime('now'), datetime('now'))",
+        (cid, project_id, ctype, cid, visibility, cid.capitalize()),
+    )
+
+
+def _grant(scope_type: str, scope_id: str, user_id: int, role: str) -> None:
+    db.conn().execute(
+        "INSERT OR REPLACE INTO memberships (scope_type, scope_id, user_id, role) "
+        "VALUES (?, ?, ?, ?)",
+        (scope_type, scope_id, user_id, role),
+    )
+
+
+def _membership(user_id: int):
+    rows = db.conn().execute(
+        "SELECT scope_type, scope_id, role FROM memberships WHERE user_id = ?",
+        (user_id,),
+    ).fetchall()
+    return {(r["scope_type"], r["scope_id"], r["role"]) for r in rows}
+
+
+def _join_requests(scope_type: str, scope_id: str):
+    rows = db.conn().execute(
+        "SELECT id, requester_user_id, requested_role, status, granted_role "
+        "FROM join_requests WHERE scope_type = ? AND scope_id = ?",
+        (scope_type, scope_id),
+    ).fetchall()
+    return [dict(r) for r in rows]
+
+
+def _join_notif_recipients(event_kind: str = "join_request_on_scope") -> set[int]:
+    return {
+        r["recipient_user_id"]
+        for r in db.conn().execute(
+            "SELECT recipient_user_id FROM notifications WHERE event_kind = ?",
+            (event_kind,),
+        )
+    }
+
+
+def _seed_world() -> None:
+    _project("ohm", "gated")
+    _collection("model", "ohm", ctype="document")
+    _collection("features", "ohm", ctype="bdd")
+    provision_user_row(user_id=2, login="ben", role="contributor")     # the joiner
+    provision_user_row(user_id=4, login="dan", role="contributor")     # collection Owner (features)
+    provision_user_row(user_id=5, login="eve", role="contributor")     # project Owner
+    provision_user_row(user_id=6, login="zoe", role="contributor")     # global Owner
+    provision_user_row(user_id=7, login="ada", role="admin")           # deployment admin
+    _grant("project", "ohm", 5, "owner")
+    _grant("collection", "features", 4, "owner")
+    _grant("global", "*", 6, "owner")
+
+
+def _login(client, uid: int, login: str, role: str = "contributor") -> None:
+    sign_in_as(client, user_id=uid, gitea_login=login, display_name=login.capitalize(), role=role)
+
+
+# ---------------------------------------------------------------------------
+# Request → cross-collection fan-out
+# ---------------------------------------------------------------------------
+
+
+def test_request_to_join_collection_fans_out_to_subtree_owners(app_with_fake_gitea):
+    """A request to join a collection lands a row and notifies every Owner whose
+    reach covers it — the collection's Owner, the project's Owner, a global
+    Owner, and the deployment admin (the cross-collection inbox) — never the
+    requester."""
+    app, _ = app_with_fake_gitea
+    with TestClient(app) as client:
+        _seed_world()
+        _login(client, 2, "ben")
+        r = client.post(
+            "/api/scopes/collection/features/join-requests",
+            json={"role": "contributor", "message": "I work on BDD corpora."},
+        )
+        assert r.status_code == 200, r.text
+        assert r.json()["status"] == "pending"
+
+        reqs = _join_requests("collection", "features")
+        assert len(reqs) == 1
+        assert reqs[0]["requester_user_id"] == 2
+        assert reqs[0]["requested_role"] == "contributor"
+        assert reqs[0]["status"] == "pending"
+
+        # Owners across the subtree are notified; ben (requester) is not.
+        recips = _join_notif_recipients()
+        assert {4, 5, 6, 7}.issubset(recips)   # dan, eve, zoe, ada
+        assert 2 not in recips
+
+
+def test_request_to_join_project_reaches_project_and_global_owners(app_with_fake_gitea):
+    """A project-scope request reaches the project's Owners + global Owners +
+    admin, but NOT a collection-only Owner (their reach doesn't cover the
+    project)."""
+    app, _ = app_with_fake_gitea
+    with TestClient(app) as client:
+        _seed_world()
+        _login(client, 2, "ben")
+        r = client.post(
+            "/api/scopes/project/ohm/join-requests",
+            json={"role": "owner"},
+        )
+        assert r.status_code == 200, r.text
+        recips = _join_notif_recipients()
+        assert {5, 6, 7}.issubset(recips)   # eve (project), zoe (global), ada (admin)
+        assert 4 not in recips               # dan is only a collection Owner
+
+
+# ---------------------------------------------------------------------------
+# Accept → writes membership + notifies
+# ---------------------------------------------------------------------------
+
+
+def test_owner_accept_writes_membership_and_notifies(app_with_fake_gitea):
+    """The collection Owner accepts; a `memberships` row is written at the
+    requested scope/role and the requester gets a join_request_accepted inbox
+    row."""
+    from app import auth
+    app, _ = app_with_fake_gitea
+    with TestClient(app) as client:
+        _seed_world()
+        _login(client, 2, "ben")
+        client.post(
+            "/api/scopes/collection/features/join-requests",
+            json={"role": "contributor"},
+        )
+        req_id = _join_requests("collection", "features")[0]["id"]
+
+        # dan (collection Owner of features) accepts.
+        _login(client, 4, "dan")
+        r = client.post(
+            f"/api/scopes/collection/features/join-requests/{req_id}/accept",
+            json={},
+        )
+        assert r.status_code == 200, r.text
+        assert r.json()["granted_role"] == "contributor"
+
+        # ben now holds the collection role and can contribute there.
+        assert ("collection", "features", "contributor") in _membership(2)
+        ben = auth.SessionUser(
+            user_id=2, gitea_id=2, gitea_login="ben", display_name="Ben",
+            email="ben@test", avatar_url="", role="contributor", permission_state="granted",
+        )
+        assert auth.can_contribute_in_collection(ben, "features") is True
+        assert auth.can_contribute_in_collection(ben, "model") is False
+
+        # the row is closed; the requester is notified.
+        assert _join_requests("collection", "features")[0]["status"] == "accepted"
+        _login(client, 2, "ben")
+        inbox = client.get("/api/notifications").json()["items"]
+        accepted = [n for n in inbox if n["event_kind"] == "join_request_accepted"]
+        assert accepted, inbox
+        assert "Features" in accepted[0]["summary"]
+
+
+def test_owner_may_narrow_role_on_accept(app_with_fake_gitea):
+    """A request for Owner may be accepted as RFC Contributor — the Owner narrows
+    the grant; the membership row carries the granted (not requested) role."""
+    app, _ = app_with_fake_gitea
+    with TestClient(app) as client:
+        _seed_world()
+        _login(client, 2, "ben")
+        client.post("/api/scopes/collection/features/join-requests", json={"role": "owner"})
+        req_id = _join_requests("collection", "features")[0]["id"]
+
+        _login(client, 5, "eve")   # project Owner — reach covers the collection
+        r = client.post(
+            f"/api/scopes/collection/features/join-requests/{req_id}/accept",
+            json={"role": "contributor"},
+        )
+        assert r.status_code == 200, r.text
+        assert ("collection", "features", "contributor") in _membership(2)
+        assert _join_requests("collection", "features")[0]["granted_role"] == "contributor"
+
+
+def test_owner_decline_notifies_and_grants_nothing(app_with_fake_gitea):
+    app, _ = app_with_fake_gitea
+    with TestClient(app) as client:
+        _seed_world()
+        _login(client, 2, "ben")
+        client.post("/api/scopes/collection/features/join-requests", json={"role": "contributor"})
+        req_id = _join_requests("collection", "features")[0]["id"]
+
+        _login(client, 4, "dan")
+        r = client.post(f"/api/scopes/collection/features/join-requests/{req_id}/decline")
+        assert r.status_code == 200, r.text
+        assert _membership(2) == set()
+        assert _join_requests("collection", "features")[0]["status"] == "declined"
+
+        _login(client, 2, "ben")
+        inbox = client.get("/api/notifications").json()["items"]
+        assert any(n["event_kind"] == "join_request_declined" for n in inbox)
+
+
+# ---------------------------------------------------------------------------
+# Gates & guards
+# ---------------------------------------------------------------------------
+
+
+def test_duplicate_pending_request_is_conflict(app_with_fake_gitea):
+    app, _ = app_with_fake_gitea
+    with TestClient(app) as client:
+        _seed_world()
+        _login(client, 2, "ben")
+        r1 = client.post("/api/scopes/collection/features/join-requests", json={"role": "contributor"})
+        assert r1.status_code == 200, r1.text
+        r2 = client.post("/api/scopes/collection/features/join-requests", json={"role": "contributor"})
+        assert r2.status_code == 409, r2.text
+
+
+def test_existing_member_cannot_request(app_with_fake_gitea):
+    """dan already owns the collection — there is nothing to request (409)."""
+    app, _ = app_with_fake_gitea
+    with TestClient(app) as client:
+        _seed_world()
+        _login(client, 4, "dan")
+        r = client.post("/api/scopes/collection/features/join-requests", json={"role": "contributor"})
+        assert r.status_code == 409, r.text
+
+
+def test_non_owner_cannot_accept(app_with_fake_gitea):
+    """A plain requester (or any non-Owner) is refused the accept action."""
+    app, _ = app_with_fake_gitea
+    with TestClient(app) as client:
+        _seed_world()
+        _login(client, 2, "ben")
+        client.post("/api/scopes/collection/features/join-requests", json={"role": "contributor"})
+        req_id = _join_requests("collection", "features")[0]["id"]
+        # provision a second plain account that tries to accept
+        provision_user_row(user_id=12, login="mal", role="contributor")
+        _login(client, 12, "mal")
+        r = client.post(
+            f"/api/scopes/collection/features/join-requests/{req_id}/accept", json={}
+        )
+        assert r.status_code == 403, r.text
+        assert _membership(2) == set()
+
+
+def test_collection_owner_cannot_act_on_sibling_collection(app_with_fake_gitea):
+    """dan owns 'features' only; a request to join 'model' is not his to act on."""
+    app, _ = app_with_fake_gitea
+    with TestClient(app) as client:
+        _seed_world()
+        _login(client, 2, "ben")
+        client.post("/api/scopes/collection/model/join-requests", json={"role": "contributor"})
+        req_id = _join_requests("collection", "model")[0]["id"]
+        _login(client, 4, "dan")
+        r = client.post(
+            f"/api/scopes/collection/model/join-requests/{req_id}/accept", json={}
+        )
+        assert r.status_code == 403, r.text
+
+
+def test_unknown_scope_404(app_with_fake_gitea):
+    app, _ = app_with_fake_gitea
+    with TestClient(app) as client:
+        _seed_world()
+        _login(client, 2, "ben")
+        assert client.post(
+            "/api/scopes/collection/nope/join-requests", json={"role": "contributor"}
+        ).status_code == 404
+        assert client.post(
+            "/api/scopes/project/nope/join-requests", json={"role": "contributor"}
+        ).status_code == 404
+        # 'global' is not a join-able scope_type.
+        assert client.post(
+            "/api/scopes/global/*/join-requests", json={"role": "contributor"}
+        ).status_code == 404
+
+
+def test_join_target_reports_eligibility(app_with_fake_gitea):
+    app, _ = app_with_fake_gitea
+    with TestClient(app) as client:
+        _seed_world()
+        # ben: eligible (granted, no role).
+        _login(client, 2, "ben")
+        t = client.get("/api/scopes/collection/features/join-target").json()
+        assert t["eligible"] is True
+        assert t["name"] == "Features"
+        assert t["current_role"] is None
+        # after requesting, already_requested flips and eligible drops.
+        client.post("/api/scopes/collection/features/join-requests", json={"role": "contributor"})
+        t2 = client.get("/api/scopes/collection/features/join-target").json()
+        assert t2["already_requested"] is True
+        assert t2["eligible"] is False
+        # dan: already a member → ineligible with current_role.
+        _login(client, 4, "dan")
+        t3 = client.get("/api/scopes/collection/features/join-target").json()
+        assert t3["eligible"] is False
+        assert t3["current_role"] == "owner"

backend/tests/test_mark_reviewed.py

@@ -0,0 +1,65 @@
+"""§22.4c — owner/admin mark-reviewed clears the flag; catalog unreviewed filter."""
+from __future__ import annotations
+
+from fastapi.testclient import TestClient
+
+from test_propose_vertical import (  # noqa: F401
+    app_with_fake_gitea, tmp_env, provision_user_row, sign_in_as,
+)
+
+
+def _seed_unreviewed_active(fake, slug="feat"):
+    """Put an active+unreviewed entry on the meta repo main + cache."""
+    from app import cache, entry as entry_mod
+    body = entry_mod.serialize(entry_mod.Entry(
+        slug=slug, title="Feat", state="active", unreviewed=True,
+        owners=["ben"], proposed_by="ben",
+    ))
+    fake.files[("wiggleverse", "meta", "main", f"rfcs/{slug}.md")] = {"content": body, "sha": "s1"}
+    cache._upsert_cached_rfc(entry_mod.parse(body), body_sha="s1")
+
+
+def test_catalog_unreviewed_filter(app_with_fake_gitea):
+    app, fake = app_with_fake_gitea
+    with TestClient(app) as client:
+        _seed_unreviewed_active(fake, "feat")
+        from app import cache, entry as entry_mod
+        ok = entry_mod.serialize(entry_mod.Entry(slug="ok", title="OK", state="active", owners=["ben"]))
+        fake.files[("wiggleverse", "meta", "main", "rfcs/ok.md")] = {"content": ok, "sha": "s2"}
+        cache._upsert_cached_rfc(entry_mod.parse(ok), body_sha="s2")
+        r = client.get("/api/rfcs", params={"unreviewed": "true"})
+        slugs = {i["slug"] for i in r.json()["items"]}
+        assert slugs == {"feat"}
+
+
+def test_mark_reviewed_clears_flag(app_with_fake_gitea):
+    from app import db
+    app, fake = app_with_fake_gitea
+    with TestClient(app) as client:
+        _seed_unreviewed_active(fake, "feat")
+        provision_user_row(user_id=1, login="ben", role="owner")
+        sign_in_as(client, user_id=1, gitea_login="ben", display_name="Ben", role="owner")
+        r = client.post("/api/projects/default/rfcs/feat/mark-reviewed")
+        assert r.status_code == 200
+        row = db.conn().execute(
+            "SELECT unreviewed, reviewed_at, reviewed_by FROM cached_rfcs WHERE slug='feat'"
+        ).fetchone()
+        assert row["unreviewed"] == 0
+        assert row["reviewed_by"] == "ben"
+        assert row["reviewed_at"]  # provenance stamped
+        # git-side: the entry file on main was rewritten with the cleared flag.
+        from app import entry as entry_mod
+        written = fake.files[("wiggleverse", "meta", "main", "rfcs/feat.md")]["content"]
+        e = entry_mod.parse(written)
+        assert e.unreviewed is False
+        assert e.reviewed_by == "ben"
+
+
+def test_mark_reviewed_forbidden_for_non_superuser(app_with_fake_gitea):
+    app, fake = app_with_fake_gitea
+    with TestClient(app) as client:
+        _seed_unreviewed_active(fake, "feat")
+        provision_user_row(user_id=2, login="carol", role="contributor")
+        sign_in_as(client, user_id=2, gitea_login="carol", display_name="Carol", role="contributor")
+        r = client.post("/api/projects/default/rfcs/feat/mark-reviewed")
+        assert r.status_code == 403

backend/tests/test_migration_027.py

@@ -0,0 +1,59 @@
+"""Migration 027 — additive §22 M3 schema (projects.type/initial_state, the
+deployment singleton, cached_rfcs review columns). No table rebuilds in Plan A."""
+from __future__ import annotations
+
+import tempfile
+from pathlib import Path
+
+from app import db
+from app.config import Config
+
+
+def _fresh_config() -> Config:
+    tmp = Path(tempfile.mkdtemp(prefix="mig027-")) / "t.db"
+    return Config(
+        gitea_url="x", gitea_bot_user="x", gitea_bot_token="x", gitea_org="x",
+        registry_repo="registry",
+        oauth_client_id="x", oauth_client_secret="x", app_url="x",
+        secret_key="x", database_path=tmp, owner_gitea_login="x",
+        webhook_secret="x",
+    )
+
+
+def test_027_adds_project_type_and_initial_state():
+    # 027 added type/initial_state to `projects`; migration 029 (three-tier)
+    # moved those per-corpus fields *down* onto `collections`. After the full
+    # migration chain they live on the collection, not the project.
+    cfg = _fresh_config()
+    db.run_migrations(cfg)
+    conn = db.connect(cfg.database_path)
+    proj_cols = {r["name"] for r in conn.execute("PRAGMA table_info(projects)")}
+    assert "type" not in proj_cols and "initial_state" not in proj_cols
+    coll_cols = {r["name"]: r for r in conn.execute("PRAGMA table_info(collections)")}
+    assert "type" in coll_cols and coll_cols["type"]["dflt_value"] == "'document'"
+    assert "initial_state" in coll_cols and coll_cols["initial_state"]["dflt_value"] == "'super-draft'"
+    conn.close()
+
+
+def test_027_creates_deployment_singleton():
+    cfg = _fresh_config()
+    db.run_migrations(cfg)
+    conn = db.connect(cfg.database_path)
+    rows = list(conn.execute("SELECT id FROM deployment"))
+    assert [r["id"] for r in rows] == [1]
+    try:
+        conn.execute("INSERT INTO deployment (id) VALUES (2)")
+        raised = False
+    except Exception:
+        raised = True
+    assert raised
+    conn.close()
+
+
+def test_027_adds_review_columns_to_cached_rfcs():
+    cfg = _fresh_config()
+    db.run_migrations(cfg)
+    conn = db.connect(cfg.database_path)
+    cols = {r["name"] for r in conn.execute("PRAGMA table_info(cached_rfcs)")}
+    assert {"unreviewed", "reviewed_at", "reviewed_by"} <= cols
+    conn.close()

backend/tests/test_migration_029_collections.py

@@ -0,0 +1,139 @@
+"""Migration 029 — the collection grain beneath projects (§22 three-tier S1).
+
+Proves: a `collections` table exists with one default collection per project
+(id='default', subfolder=repo root); the per-corpus fields (type, initial_state)
+moved off `projects`; the 13 entry-corpus tables re-key (project_id,slug) ->
+(collection_id,slug) with the composite PK/FK enforced; and project_members
+generalises into memberships(scope_type, …) with the role enum collapsed.
+Template: test_migration_028_project_scoped_keys.py.
+"""
+from __future__ import annotations
+
+import sqlite3
+import tempfile
+from pathlib import Path
+
+import pytest
+
+from app import db
+
+
+class _Cfg:
+    def __init__(self, path):
+        self.database_path = path
+
+
+def _fresh_db():
+    d = tempfile.mkdtemp()
+    path = Path(d) / "t.db"
+    db.run_migrations(_Cfg(str(path)))
+    return db.connect(str(path))
+
+
+def test_collections_table_exists_with_default_per_project():
+    conn = _fresh_db()
+    cols = {r["name"] for r in conn.execute("PRAGMA table_info(collections)")}
+    assert {"id", "project_id", "type", "subfolder",
+            "initial_state", "visibility", "name", "registry_sha"} <= cols
+    # one default collection seeded for the bootstrap 'default' project (026)
+    row = conn.execute(
+        "SELECT id, project_id, subfolder FROM collections WHERE project_id='default'"
+    ).fetchone()
+    assert row is not None
+    assert row["id"] == "default"
+    assert row["subfolder"] == ""  # repo root
+
+
+def test_per_corpus_fields_moved_off_projects():
+    conn = _fresh_db()
+    proj_cols = {r["name"] for r in conn.execute("PRAGMA table_info(projects)")}
+    assert "type" not in proj_cols
+    assert "initial_state" not in proj_cols
+    # projects keeps the grouping-tier fields
+    assert {"id", "name", "content_repo", "visibility"} <= proj_cols
+
+
+def test_entry_tables_rekeyed_to_collection_id():
+    conn = _fresh_db()
+    for t in ("cached_rfcs", "cached_branches", "stars", "watches",
+              "rfc_collaborators", "contribution_requests", "proposed_use_cases",
+              "branch_visibility", "branch_contribute_grants", "pr_seen",
+              "branch_chat_seen", "funder_consents", "rfc_invitations"):
+        cols = {r["name"] for r in conn.execute(f"PRAGMA table_info({t})")}
+        assert "collection_id" in cols, f"{t} missing collection_id"
+        assert "project_id" not in cols, f"{t} still has project_id"
+
+
+def test_cached_rfcs_pk_is_collection_slug():
+    conn = _fresh_db()
+    # a second collection under the default project
+    conn.execute(
+        "INSERT INTO collections (id, project_id, type, subfolder, initial_state, visibility, name) "
+        "VALUES ('c2','default','document','specs','active','public','Specs')"
+    )
+    conn.execute("INSERT INTO cached_rfcs (slug, title, state, collection_id) VALUES ('intro','A','active','default')")
+    conn.execute("INSERT INTO cached_rfcs (slug, title, state, collection_id) VALUES ('intro','B','active','c2')")
+    n = conn.execute("SELECT COUNT(*) c FROM cached_rfcs WHERE slug='intro'").fetchone()["c"]
+    assert n == 2
+    with pytest.raises(sqlite3.IntegrityError):
+        conn.execute("INSERT INTO cached_rfcs (slug, title, state, collection_id) VALUES ('intro','dup','active','default')")
+
+
+def test_cached_rfcs_collection_fk_enforced():
+    conn = _fresh_db()
+    conn.execute("PRAGMA foreign_keys=ON")
+    with pytest.raises(sqlite3.IntegrityError):
+        conn.execute("INSERT INTO cached_rfcs (slug, title, state, collection_id) VALUES ('x','X','active','nope')")
+
+
+def test_collaborator_fk_is_composite_on_collection():
+    conn = _fresh_db()
+    conn.execute(
+        "INSERT INTO collections (id, project_id, type, subfolder, initial_state, visibility, name) "
+        "VALUES ('c2','default','document','specs','active','public','Specs')"
+    )
+    conn.execute("INSERT INTO cached_rfcs (slug, title, state, collection_id) VALUES ('intro','A','active','c2')")
+    conn.execute("INSERT INTO users (id, gitea_login, display_name, role) VALUES (1,'a','A','contributor')")
+    conn.execute("PRAGMA foreign_keys=ON")
+    conn.execute(
+        "INSERT INTO rfc_collaborators (rfc_slug, user_id, role_in_rfc, collection_id) "
+        "VALUES ('intro',1,'contributor','c2')"
+    )
+    with pytest.raises(sqlite3.IntegrityError):
+        # same slug, a collection with no such entry — composite FK rejects
+        conn.execute(
+            "INSERT INTO rfc_collaborators (rfc_slug, user_id, role_in_rfc, collection_id) "
+            "VALUES ('intro',1,'contributor','default')"
+        )
+
+
+def test_stars_unique_now_scoped_by_collection():
+    conn = _fresh_db()
+    conn.execute(
+        "INSERT INTO collections (id, project_id, type, subfolder, initial_state, visibility, name) "
+        "VALUES ('c2','default','document','specs','active','public','Specs')"
+    )
+    conn.execute("INSERT INTO users (id, gitea_login, display_name, role) VALUES (1,'a','A','contributor')")
+    conn.execute("INSERT INTO cached_rfcs (slug, title, state, collection_id) VALUES ('intro','A','active','default')")
+    conn.execute("INSERT INTO cached_rfcs (slug, title, state, collection_id) VALUES ('intro','B','active','c2')")
+    conn.execute("INSERT INTO stars (user_id, rfc_slug, collection_id) VALUES (1,'intro','default')")
+    conn.execute("INSERT INTO stars (user_id, rfc_slug, collection_id) VALUES (1,'intro','c2')")
+    with pytest.raises(sqlite3.IntegrityError):
+        conn.execute("INSERT INTO stars (user_id, rfc_slug, collection_id) VALUES (1,'intro','default')")
+
+
+def test_memberships_table_replaces_project_members():
+    conn = _fresh_db()
+    cols = {r["name"] for r in conn.execute("PRAGMA table_info(memberships)")}
+    assert {"scope_type", "scope_id", "user_id", "role", "granted_by", "granted_at"} <= cols
+    # project_members is gone
+    assert conn.execute(
+        "SELECT name FROM sqlite_master WHERE type='table' AND name='project_members'"
+    ).fetchone() is None
+    conn.execute("INSERT INTO users (id, gitea_login, display_name, role) VALUES (9,'x','X','contributor')")
+    conn.execute("INSERT INTO memberships (scope_type, scope_id, user_id, role) VALUES ('project','default',9,'owner')")
+    # scope_type and role are CHECK-constrained
+    with pytest.raises(sqlite3.IntegrityError):
+        conn.execute("INSERT INTO memberships (scope_type, scope_id, user_id, role) VALUES ('bogus','default',9,'owner')")
+    with pytest.raises(sqlite3.IntegrityError):
+        conn.execute("INSERT INTO memberships (scope_type, scope_id, user_id, role) VALUES ('project','default',9,'viewer')")

backend/tests/test_migration_030_global_scope.py

@@ -0,0 +1,91 @@
+"""Migration 030 — the global-scope grant (§22 three-tier S3).
+
+Proves: `memberships.scope_type` now admits 'global' alongside 'project' and
+'collection' (§B.2's four-layer resolver), existing rows survive the rebuild,
+and the UNIQUE(scope_type, scope_id, user_id) shape is preserved.
+Template: test_migration_029_collections.py.
+"""
+from __future__ import annotations
+
+import sqlite3
+import tempfile
+from pathlib import Path
+
+import pytest
+
+from app import db
+
+
+class _Cfg:
+    def __init__(self, path):
+        self.database_path = path
+
+
+def _fresh_db():
+    d = tempfile.mkdtemp()
+    path = Path(d) / "t.db"
+    db.run_migrations(_Cfg(str(path)))
+    return db.connect(str(path))
+
+
+def _add_user(conn, uid, login):
+    conn.execute(
+        "INSERT INTO users (id, gitea_id, gitea_login, display_name, role) "
+        "VALUES (?, ?, ?, ?, 'contributor')",
+        (uid, uid, login, login.capitalize()),
+    )
+
+
+def test_global_scope_type_is_accepted():
+    conn = _fresh_db()
+    _add_user(conn, 1, "cleo")
+    # global grant — the new tier — is accepted.
+    conn.execute(
+        "INSERT INTO memberships (scope_type, scope_id, user_id, role) "
+        "VALUES ('global', '*', 1, 'contributor')"
+    )
+    row = conn.execute(
+        "SELECT scope_type, scope_id, role FROM memberships WHERE user_id = 1"
+    ).fetchone()
+    assert row["scope_type"] == "global"
+    assert row["scope_id"] == "*"
+    assert row["role"] == "contributor"
+
+
+def test_project_and_collection_scopes_still_accepted():
+    conn = _fresh_db()
+    _add_user(conn, 1, "ben")
+    conn.execute(
+        "INSERT INTO memberships (scope_type, scope_id, user_id, role) "
+        "VALUES ('project', 'default', 1, 'owner')"
+    )
+    conn.execute(
+        "INSERT INTO memberships (scope_type, scope_id, user_id, role) "
+        "VALUES ('collection', 'default', 1, 'contributor')"
+    )
+    n = conn.execute("SELECT COUNT(*) AS n FROM memberships WHERE user_id = 1").fetchone()["n"]
+    assert n == 2
+
+
+def test_unknown_scope_type_still_rejected():
+    conn = _fresh_db()
+    _add_user(conn, 1, "x")
+    with pytest.raises(sqlite3.IntegrityError):
+        conn.execute(
+            "INSERT INTO memberships (scope_type, scope_id, user_id, role) "
+            "VALUES ('deployment', '*', 1, 'owner')"
+        )
+
+
+def test_one_global_grant_per_user():
+    conn = _fresh_db()
+    _add_user(conn, 1, "cleo")
+    conn.execute(
+        "INSERT INTO memberships (scope_type, scope_id, user_id, role) "
+        "VALUES ('global', '*', 1, 'contributor')"
+    )
+    with pytest.raises(sqlite3.IntegrityError):
+        conn.execute(
+            "INSERT INTO memberships (scope_type, scope_id, user_id, role) "
+            "VALUES ('global', '*', 1, 'owner')"
+        )

backend/tests/test_migration_032_join_requests.py

@@ -0,0 +1,95 @@
+"""Migration 032 — the join_requests table (§22.8 S6).
+
+Proves: the table exists with its CHECK constraints (scope_type ∈
+{project,collection}; role/status enums), the one-open-per-(scope,user) partial
+unique index holds, and a decided request frees a fresh ask.
+Template: test_migration_030_global_scope.py.
+"""
+from __future__ import annotations
+
+import sqlite3
+import tempfile
+from pathlib import Path
+
+import pytest
+
+from app import db
+
+
+class _Cfg:
+    def __init__(self, path):
+        self.database_path = path
+
+
+def _fresh_db():
+    d = tempfile.mkdtemp()
+    path = Path(d) / "t.db"
+    db.run_migrations(_Cfg(str(path)))
+    return db.connect(str(path))
+
+
+def _add_user(conn, uid, login):
+    conn.execute(
+        "INSERT INTO users (id, gitea_id, gitea_login, display_name, role) "
+        "VALUES (?, ?, ?, ?, 'contributor')",
+        (uid, uid, login, login.capitalize()),
+    )
+
+
+def _request(conn, scope_type="collection", scope_id="features", uid=1, role="contributor"):
+    conn.execute(
+        "INSERT INTO join_requests (scope_type, scope_id, requester_user_id, requested_role) "
+        "VALUES (?, ?, ?, ?)",
+        (scope_type, scope_id, uid, role),
+    )
+
+
+def test_join_request_row_round_trips():
+    conn = _fresh_db()
+    _add_user(conn, 1, "ben")
+    _request(conn)
+    row = conn.execute("SELECT * FROM join_requests WHERE requester_user_id = 1").fetchone()
+    assert row["scope_type"] == "collection"
+    assert row["requested_role"] == "contributor"
+    assert row["status"] == "pending"
+    assert row["granted_role"] is None
+
+
+def test_global_scope_type_is_rejected():
+    conn = _fresh_db()
+    _add_user(conn, 1, "ben")
+    with pytest.raises(sqlite3.IntegrityError):
+        _request(conn, scope_type="global", scope_id="*")
+
+
+def test_bad_role_and_status_rejected():
+    conn = _fresh_db()
+    _add_user(conn, 1, "ben")
+    with pytest.raises(sqlite3.IntegrityError):
+        _request(conn, role="viewer")
+    with pytest.raises(sqlite3.IntegrityError):
+        conn.execute(
+            "INSERT INTO join_requests (scope_type, scope_id, requester_user_id, requested_role, status) "
+            "VALUES ('project', 'ohm', 1, 'owner', 'maybe')"
+        )
+
+
+def test_one_open_request_per_scope_user():
+    conn = _fresh_db()
+    _add_user(conn, 1, "ben")
+    _request(conn)
+    with pytest.raises(sqlite3.IntegrityError):
+        _request(conn)
+
+
+def test_decided_request_frees_a_fresh_ask():
+    conn = _fresh_db()
+    _add_user(conn, 1, "ben")
+    _request(conn)
+    conn.execute("UPDATE join_requests SET status = 'declined' WHERE requester_user_id = 1")
+    # a second open ask is now allowed
+    _request(conn)
+    n = conn.execute(
+        "SELECT COUNT(*) AS n FROM join_requests WHERE requester_user_id = 1"
+    ).fetchone()["n"]
+    assert n == 2

backend/tests/test_multi_project_authz_vertical.py

@@ -0,0 +1,358 @@
+"""Slice M2 — project-scoped authorization + the §22.7 resolver.
+
+M1 laid the schema spine (the `projects` / `project_members` tables and the
+`project_id` column on every slug-bearing table). M2 builds the resolver on top:
+the most-permissive union of the deployment role (§6.1), the project role
+(§22.6), and the per-RFC authority (§6.3/§12), with the §22.5 visibility gate
+subtractive on top (§22.7).
+
+Two operator decisions are pinned here as executable expectations:
+
+  * implicit-on-public — a granted deployment `contributor` keeps its
+    pre-multi-project write *baseline* on a `public` project (propose freely;
+    an owned RFC's discuss/contribute still needs the per-RFC invite) with no
+    project_members row. So the single public default project behaves exactly
+    as it did before M2 (verified across the rest of the suite, and the
+    `*_public_*` tests below).
+  * preserve curation — the implicit-public baseline does NOT override per-RFC
+    owner curation; only an *explicit* project_contributor/admin grant (or a
+    deployment owner/admin) bypasses it.
+
+Everything is exercised on the single `default` project by flipping its
+visibility and granting/revoking `project_members` roles — the M2 slice is
+verifiable without a second project (which arrives with M3's registry mirror).
+"""
+from __future__ import annotations
+
+from fastapi.testclient import TestClient
+
+from test_propose_vertical import (  # noqa: F401 — fixtures land via import
+    app_with_fake_gitea,
+    provision_user_row,
+    sign_in_as,
+    tmp_env,
+)
+
+
+# ---------------------------------------------------------------------------
+# Helpers
+# ---------------------------------------------------------------------------
+
+
+def _su(user_id: int, login: str, role: str, *, state: str = "granted"):
+    """A SessionUser handle for direct resolver calls (the endpoint tests use
+    sign_in_as instead)."""
+    from app import auth
+
+    return auth.SessionUser(
+        user_id=user_id,
+        gitea_id=user_id,
+        gitea_login=login,
+        display_name=login.capitalize(),
+        email=f"{login}@test",
+        avatar_url="",
+        role=role,
+        permission_state=state,
+    )
+
+
+def _set_visibility(project_id: str, visibility: str) -> None:
+    from app import db
+
+    db.conn().execute(
+        "UPDATE projects SET visibility = ? WHERE id = ?", (visibility, project_id)
+    )
+
+
+# §22 three-tier (§B.3): M2's three project roles collapse to {owner,
+# contributor} in the unified `memberships` table at the project's default
+# collection. The read-only `viewer` tier is deferred (folded into contributor
+# for this pass), so the legacy role names map: admin→owner, contributor and
+# viewer→contributor.
+_ROLE_MAP = {
+    "project_admin": "owner",
+    "project_contributor": "contributor",
+    "project_viewer": "contributor",
+}
+
+
+def _add_member(project_id: str, user_id: int, role: str) -> None:
+    from app import collections as collections_mod, db
+
+    cid = collections_mod.default_collection_id(project_id)
+    db.conn().execute(
+        "INSERT OR REPLACE INTO memberships (scope_type, scope_id, user_id, role) "
+        "VALUES ('collection', ?, ?, ?)",
+        (cid, user_id, _ROLE_MAP[role]),
+    )
+
+
+def _remove_member(project_id: str, user_id: int) -> None:
+    from app import collections as collections_mod, db
+
+    cid = collections_mod.default_collection_id(project_id)
+    db.conn().execute(
+        "DELETE FROM memberships WHERE scope_type = 'collection' AND scope_id = ? AND user_id = ?",
+        (cid, user_id),
+    )
+
+
+def _seed_rfc(slug: str, *, state: str = "active", owners=None, project_id: str = "default") -> None:
+    """A minimal cached_rfcs row — enough for the authz gates (state, owners,
+    collection grain). The entry lands in the project's default collection
+    (id == project_id for the single 'default' project under test)."""
+    import json
+
+    from app import collections as collections_mod, db
+
+    cid = collections_mod.default_collection_id(project_id)
+    db.conn().execute(
+        """
+        INSERT OR REPLACE INTO cached_rfcs
+            (slug, title, state, owners_json, arbiters_json, tags_json, collection_id)
+        VALUES (?, ?, ?, ?, '[]', '[]', ?)
+        """,
+        (slug, slug.capitalize(), state, json.dumps(owners or []), cid),
+    )
+
+
+# ---------------------------------------------------------------------------
+# 1. The §22.7 resolver — tier composition
+# ---------------------------------------------------------------------------
+
+
+def test_resolver_public_project_tiers(app_with_fake_gitea):
+    from app import auth
+
+    app, _ = app_with_fake_gitea
+    with TestClient(app):
+        provision_user_row(user_id=1, login="alice", role="contributor")
+        provision_user_row(user_id=2, login="ben", role="owner")
+        contributor = _su(1, "alice", "contributor")
+        owner = _su(2, "ben", "owner")
+
+        # default is public — read open to everyone incl. anonymous.
+        assert auth.can_read_project(None, "default") is True
+        assert auth.can_read_project(contributor, "default") is True
+
+        # implicit-on-public: a granted deployment contributor carries the
+        # write baseline without a project_members row.
+        assert auth.can_contribute_in_project(contributor, "default") is True
+        assert auth.can_discuss_in_project(contributor, "default") is True
+
+        # ... but it is NOT project_admin (curation/override authority).
+        assert auth.is_project_superuser(contributor, "default") is False
+        # a deployment owner/admin is a superuser in every project.
+        assert auth.is_project_superuser(owner, "default") is True
+
+        # a pending contributor has no write standing (the §6 admission floor).
+        pending = _su(1, "alice", "contributor", state="pending")
+        assert auth.can_contribute_in_project(pending, "default") is False
+
+
+def test_resolver_gated_project_requires_membership(app_with_fake_gitea):
+    from app import auth
+
+    app, _ = app_with_fake_gitea
+    with TestClient(app):
+        provision_user_row(user_id=1, login="alice", role="contributor")
+        provision_user_row(user_id=2, login="ben", role="owner")
+        _set_visibility("default", "gated")
+        contributor = _su(1, "alice", "contributor")
+        owner = _su(2, "ben", "owner")
+
+        # gated: no membership → invisible and no standing.
+        assert auth.can_read_project(None, "default") is False
+        assert auth.can_read_project(contributor, "default") is False
+        assert auth.can_contribute_in_project(contributor, "default") is False
+
+        # deployment owner is a superuser regardless of membership.
+        assert auth.can_read_project(owner, "default") is True
+        assert auth.is_project_superuser(owner, "default") is True
+
+        # §22 three-tier (§B.3): the read-only viewer tier is deferred — the
+        # smallest grant is `contributor`, which grants read + discuss +
+        # contribute across the subtree.
+        _add_member("default", 1, "project_contributor")
+        assert auth.can_read_project(contributor, "default") is True
+        assert auth.can_discuss_in_project(contributor, "default") is True
+        assert auth.can_contribute_in_project(contributor, "default") is True
+        assert auth.is_project_superuser(contributor, "default") is False
+
+        # project_admin → owner → superuser within the project.
+        _add_member("default", 1, "project_admin")
+        assert auth.is_project_superuser(contributor, "default") is True
+
+
+# ---------------------------------------------------------------------------
+# 2. Public default unchanged — the regression floor (curation preserved)
+# ---------------------------------------------------------------------------
+
+
+def test_public_per_rfc_curation_preserved(app_with_fake_gitea):
+    """On the public default project a granted contributor still cannot
+    discuss an *owned* RFC without a per-RFC invite (the v0.16.0 contract);
+    but an unclaimed (no-owners) entry stays open. This is the implicit-public
+    baseline with curation preserved."""
+    from app import auth
+
+    app, _ = app_with_fake_gitea
+    with TestClient(app):
+        provision_user_row(user_id=1, login="alice", role="contributor")
+        provision_user_row(user_id=2, login="bob", role="contributor")
+        bob = _su(2, "bob", "contributor")
+
+        _seed_rfc("owned", state="active", owners=["alice"])
+        assert auth.can_discuss_rfc(bob, "owned") is False
+        assert auth.can_contribute_to_rfc(bob, "owned") is False
+
+        _seed_rfc("draft", state="super-draft", owners=[])
+        assert auth.can_discuss_rfc(bob, "draft") is True
+        assert auth.can_contribute_to_rfc(bob, "draft") is True
+
+
+def test_public_read_open_write_gated_endpoints(app_with_fake_gitea):
+    app, _ = app_with_fake_gitea
+    with TestClient(app) as client:
+        provision_user_row(user_id=2, login="bob", role="contributor")
+        _seed_rfc("ohm", state="active", owners=["alice"])
+
+        # anonymous can read the entry on a public project.
+        r = client.get("/api/rfcs/ohm")
+        assert r.status_code == 200, r.text
+
+        # anonymous cannot open a discussion thread (401, the §6 write floor).
+        r = client.post("/api/rfcs/ohm/discussion/threads", json={"message": "hi"})
+        assert r.status_code == 401
+
+
+# ---------------------------------------------------------------------------
+# 3. The §22.5 visibility gate — 404 to non-members on read
+# ---------------------------------------------------------------------------
+
+
+def test_gated_project_404s_non_members(app_with_fake_gitea):
+    app, _ = app_with_fake_gitea
+    with TestClient(app) as client:
+        provision_user_row(user_id=1, login="alice", role="contributor")
+        provision_user_row(user_id=2, login="bob", role="contributor")
+        provision_user_row(user_id=3, login="ben", role="owner")
+        _seed_rfc("sekret", state="active", owners=["alice"])
+        _set_visibility("default", "gated")
+
+        # anonymous → 404 (indistinguishable from an unknown slug).
+        assert client.get("/api/rfcs/sekret").status_code == 404
+
+        # signed-in non-member → 404 on the entry and its discussion.
+        sign_in_as(client, user_id=2, gitea_login="bob", display_name="Bob", role="contributor")
+        assert client.get("/api/rfcs/sekret").status_code == 404
+        assert client.get("/api/rfcs/sekret/discussion/threads").status_code == 404
+        # the gated entry never surfaces in the non-member's catalog.
+        assert client.get("/api/rfcs").json()["items"] == []
+
+        # a project_viewer member can read again.
+        _add_member("default", 2, "project_viewer")
+        assert client.get("/api/rfcs/sekret").status_code == 200
+        assert [i["slug"] for i in client.get("/api/rfcs").json()["items"]] == ["sekret"]
+
+        # a deployment owner can always read.
+        sign_in_as(client, user_id=3, gitea_login="ben", display_name="Ben", role="owner")
+        assert client.get("/api/rfcs/sekret").status_code == 200
+
+
+# ---------------------------------------------------------------------------
+# 4. The contribution gate on a gated project (401/403)
+# ---------------------------------------------------------------------------
+
+
+def test_gated_propose_requires_project_contributor(app_with_fake_gitea):
+    """Propose checks project-level contribute standing before any Gitea
+    work, so the gate is observable as a 403 (gated, non-member) without
+    seeding the success path."""
+    app, _ = app_with_fake_gitea
+    with TestClient(app) as client:
+        provision_user_row(user_id=2, login="bob", role="contributor")
+        _set_visibility("default", "gated")
+        sign_in_as(client, user_id=2, gitea_login="bob", display_name="Bob", role="contributor")
+
+        body = {"slug": "newidea", "title": "New Idea", "pitch": "A pitch.", "tags": []}
+        assert client.post("/api/rfcs/propose", json=body).status_code == 403
+
+        # grant project_contributor — the project gate now passes (the request
+        # proceeds past the gate; we assert only that it is no longer 403).
+        _add_member("default", 2, "project_contributor")
+        assert client.post("/api/rfcs/propose", json=body).status_code != 403
+
+
+def test_gated_member_can_discuss_and_contribute(app_with_fake_gitea):
+    from app import auth
+
+    app, _ = app_with_fake_gitea
+    with TestClient(app) as client:
+        provision_user_row(user_id=2, login="bob", role="contributor")
+        _seed_rfc("spec", state="super-draft", owners=[])
+        _set_visibility("default", "gated")
+        bob = _su(2, "bob", "contributor")
+
+        # non-member: discussion thread create → 404 (visibility, before the
+        # write gate even applies).
+        sign_in_as(client, user_id=2, gitea_login="bob", display_name="Bob", role="contributor")
+        assert client.post("/api/rfcs/spec/discussion/threads", json={"message": "q"}).status_code == 404
+
+        # §22 three-tier (§B.3): a `contributor` member can both discuss and
+        # contribute (the viewer-only read tier is deferred this pass).
+        _add_member("default", 2, "project_contributor")
+        r = client.post("/api/rfcs/spec/discussion/threads", json={"message": "q"})
+        assert r.status_code == 200, r.text
+        assert auth.can_contribute_to_rfc(bob, "spec") is True
+
+
+# ---------------------------------------------------------------------------
+# 5. Union of tiers + subtractive visibility gate
+# ---------------------------------------------------------------------------
+
+
+def test_per_rfc_authority_unions_then_yields_to_visibility(app_with_fake_gitea):
+    from app import auth
+    from test_propose_vertical import grant_rfc_collaborator
+
+    app, _ = app_with_fake_gitea
+    with TestClient(app):
+        provision_user_row(user_id=2, login="bob", role="contributor")
+        _seed_rfc("owned", state="active", owners=["alice"])
+        bob = _su(2, "bob", "contributor")
+
+        # public + per-RFC collaborator(contributor) → contribute (union term).
+        grant_rfc_collaborator(user_id=2, rfc_slug="owned", role_in_rfc="contributor")
+        assert auth.can_contribute_to_rfc(bob, "owned") is True
+
+        # flip to gated: the §22.5 gate is subtractive — the per-RFC grant no
+        # longer suffices without project membership.
+        _set_visibility("default", "gated")
+        assert auth.can_contribute_to_rfc(bob, "owned") is False
+
+        # restore read via project membership → the per-RFC union applies again.
+        _add_member("default", 2, "project_viewer")
+        assert auth.can_contribute_to_rfc(bob, "owned") is True
+
+
+# ---------------------------------------------------------------------------
+# 6. Revocation takes effect on the next call
+# ---------------------------------------------------------------------------
+
+
+def test_revoking_membership_revokes_access(app_with_fake_gitea):
+    from app import auth
+
+    app, _ = app_with_fake_gitea
+    with TestClient(app):
+        provision_user_row(user_id=2, login="bob", role="contributor")
+        _set_visibility("default", "gated")
+        bob = _su(2, "bob", "contributor")
+
+        _add_member("default", 2, "project_contributor")
+        assert auth.can_contribute_in_project(bob, "default") is True
+
+        _remove_member("default", 2)
+        assert auth.can_read_project(bob, "default") is False
+        assert auth.can_contribute_in_project(bob, "default") is False

backend/tests/test_multi_project_spine_vertical.py

@@ -0,0 +1,147 @@
+"""Slice M1+M3 — the §22 multi-project spine.
+
+Migration 026 introduces the `projects` and `project_members` tables, seeds
+the single `default` project (the N=1 case, §22.13), and threads a
+`project_id` column onto every slug-bearing table, backfilled to `default`.
+M3 retires the META_REPO startup backfill; content_repo now comes from the
+registry mirror (projects.yaml in REGISTRY_REPO). These tests prove the
+spine lands without disturbing the single-project app.
+"""
+from __future__ import annotations
+
+from fastapi.testclient import TestClient
+
+from test_propose_vertical import (  # noqa: F401
+    app_with_fake_gitea,
+    tmp_env,
+)
+
+# §22 three-tier (migration 029): the entry-corpus grain is the collection, so
+# the 13 tables migration 028 keyed by project_id re-key to collection_id. The
+# remaining tables 026 tagged keep their denormalised project_id (project grain).
+COLLECTION_TABLES = [
+    "cached_rfcs", "cached_branches", "branch_visibility",
+    "branch_contribute_grants", "stars", "pr_seen", "branch_chat_seen",
+    "watches", "funder_consents", "rfc_invitations", "rfc_collaborators",
+    "proposed_use_cases", "contribution_requests",
+]
+PROJECT_TAG_TABLES = [
+    "cached_prs", "threads", "changes", "notifications", "actions",
+    "pr_resolution_branches",
+]
+
+
+def test_default_project_seeded_and_backfilled(app_with_fake_gitea):
+    from app import db
+
+    app, _ = app_with_fake_gitea
+    with TestClient(app):
+        rows = list(db.conn().execute(
+            "SELECT id, name, visibility, content_repo FROM projects"
+        ))
+        assert len(rows) == 1
+        row = rows[0]
+        assert row["id"] == "default"
+        # public preserves the pre-multi-project open-by-default posture.
+        assert row["visibility"] == "public"
+        # M3: content_repo now comes from the registry mirror (projects.yaml),
+        # not the retired META_REPO startup backfill.
+        assert row["content_repo"] == "meta"
+
+
+def test_grain_columns_on_every_slug_table(app_with_fake_gitea):
+    from app import db
+
+    app, _ = app_with_fake_gitea
+    with TestClient(app):
+        # The entry-corpus tables key on collection_id (NOT NULL, 'default').
+        for table in COLLECTION_TABLES:
+            cols = {r["name"]: r for r in db.conn().execute(f"PRAGMA table_info({table})")}
+            assert "collection_id" in cols, f"{table} missing collection_id"
+            assert "project_id" not in cols, f"{table} should no longer have project_id"
+            col = cols["collection_id"]
+            assert col["notnull"] == 1, f"{table}.collection_id should be NOT NULL"
+            assert col["dflt_value"] == "'default'", f"{table}.collection_id default"
+        # The project-tag tables keep their denormalised project_id.
+        for table in PROJECT_TAG_TABLES:
+            cols = {r["name"] for r in db.conn().execute(f"PRAGMA table_info({table})")}
+            assert "project_id" in cols, f"{table} missing project_id tag"
+
+
+def test_existing_row_backfills_to_default(app_with_fake_gitea):
+    """A row inserted the old way (no collection grain) lands in the default
+    collection — the trick that keeps every pre-three-tier INSERT working."""
+    from app import db
+
+    app, _ = app_with_fake_gitea
+    with TestClient(app):
+        db.conn().execute(
+            "INSERT INTO cached_rfcs (slug, title, state) VALUES (?, ?, ?)",
+            ("human", "Human", "active"),
+        )
+        got = db.conn().execute(
+            "SELECT collection_id FROM cached_rfcs WHERE slug = 'human'"
+        ).fetchone()["collection_id"]
+        assert got == "default"
+
+
+def test_memberships_table_shape(app_with_fake_gitea):
+    from app import db
+
+    app, _ = app_with_fake_gitea
+    with TestClient(app):
+        # §22 three-tier: project_members generalised into memberships.
+        assert db.conn().execute(
+            "SELECT name FROM sqlite_master WHERE type='table' AND name='project_members'"
+        ).fetchone() is None
+        cols = {r["name"] for r in db.conn().execute("PRAGMA table_info(memberships)")}
+        assert {"scope_type", "scope_id", "user_id", "role", "granted_by", "granted_at"} <= cols
+        db.conn().execute(
+            "INSERT INTO users (id, display_name, role) VALUES (1, 'Ben', 'owner')"
+        )
+        db.conn().execute(
+            "INSERT INTO memberships (scope_type, scope_id, user_id, role) "
+            "VALUES ('collection', 'default', 1, 'owner')"
+        )
+        import sqlite3
+        try:
+            db.conn().execute(
+                "INSERT INTO memberships (scope_type, scope_id, user_id, role) "
+                "VALUES ('collection', 'default', 1, 'nonsense')"
+            )
+            assert False, "CHECK should reject an unknown role"
+        except sqlite3.IntegrityError:
+            pass
+
+
+def test_registry_mirror_is_idempotent(app_with_fake_gitea):
+    """Re-running the registry mirror is safe — it upserts (overwrites) the
+    projects row from projects.yaml each time without raising. M3 retirement
+    of seed_default_project: the registry mirror is now the sole authority."""
+    import asyncio
+    from app import db, registry as registry_mod
+
+    app, _ = app_with_fake_gitea
+    with TestClient(app):
+        before = db.conn().execute("SELECT COUNT(*) AS n FROM projects").fetchone()["n"]
+        cfg = app.state.config
+        gitea = app.state.gitea
+        asyncio.run(registry_mod.refresh_registry(cfg, gitea))
+        after = db.conn().execute("SELECT COUNT(*) AS n FROM projects").fetchone()["n"]
+        assert after == before
+        row = db.conn().execute(
+            "SELECT content_repo FROM projects WHERE id='default'"
+        ).fetchone()
+        assert row["content_repo"] == "meta"
+
+
+def test_registry_repo_config_wired(app_with_fake_gitea, monkeypatch):
+    from app.config import load_config
+
+    monkeypatch.setenv("REGISTRY_REPO", "wiggleverse-registry")
+    assert load_config().registry_repo == "wiggleverse-registry"
+    # M3: REGISTRY_REPO is now required — absent raises RuntimeError.
+    monkeypatch.delenv("REGISTRY_REPO", raising=False)
+    import pytest
+    with pytest.raises(RuntimeError, match="REGISTRY_REPO"):
+        load_config()

backend/tests/test_project_scoped_propose.py

@@ -0,0 +1,79 @@
+"""§22.4 (Plan B write): proposing a new entry into a *specific* project lands
+it in that project's content repo and surfaces under that project's proposals,
+isolated from the default project."""
+from __future__ import annotations
+
+from fastapi.testclient import TestClient
+
+from test_propose_vertical import (  # noqa: F401
+    app_with_fake_gitea, tmp_env, provision_user_row, sign_in_as,
+)
+
+
+def _register_ecomm(fake):
+    from app import db
+    db.conn().execute(
+        "INSERT OR IGNORE INTO projects (id, name, content_repo, visibility) "
+        "VALUES ('ecomm', 'Ecomm', 'ecomm-content', 'public')"
+    )
+    db.conn().execute(
+        "INSERT OR IGNORE INTO collections (id, project_id, type, subfolder, initial_state, visibility, name) "
+        "VALUES ('ecomm', 'ecomm', 'document', '', 'super-draft', 'public', 'Ecomm')"
+    )
+    fake._seed_repo("wiggleverse", "ecomm-content")
+
+
+def test_propose_into_second_project_lands_scoped(app_with_fake_gitea):
+    app, fake = app_with_fake_gitea
+    with TestClient(app) as client:
+        _register_ecomm(fake)
+        provision_user_row(user_id=3, login="alice", role="contributor")
+        # §22 S3: the grandfathered implicit-public baseline covers only the N=1
+        # `default` collection; a second project requires an explicit scope grant
+        # to write. Grant alice contributor at the ecomm project.
+        from app import db
+        db.conn().execute(
+            "INSERT OR REPLACE INTO memberships (scope_type, scope_id, user_id, role) "
+            "VALUES ('project', 'ecomm', 3, 'contributor')")
+        sign_in_as(client, user_id=3, gitea_login="alice", display_name="Alice",
+                   role="contributor", email="alice@test")
+        r = client.post("/api/projects/ecomm/rfcs/propose", json={
+            "title": "Cart", "slug": "cart", "pitch": "why a cart", "tags": [],
+        })
+        assert r.status_code == 200, r.text
+
+        # The idea PR shows under ecomm's proposals, not the default's.
+        e = {i["slug"] for i in client.get("/api/projects/ecomm/proposals").json()["items"]}
+        d = {i["slug"] for i in client.get("/api/projects/default/proposals").json()["items"]}
+        assert "cart" in e
+        assert "cart" not in d
+
+        # It landed in ecomm's content repo, not the default 'meta' repo.
+        assert ("wiggleverse", "ecomm-content") in {
+            (o, rp) for (o, rp) in fake.branches if rp == "ecomm-content"
+        }
+        assert any(
+            br.startswith("propose/cart")
+            for br in fake.branches.get(("wiggleverse", "ecomm-content"), {})
+        )
+
+
+def test_propose_into_gated_project_404s_for_non_member(app_with_fake_gitea):
+    app, _ = app_with_fake_gitea
+    from app import db
+    with TestClient(app) as client:
+        db.conn().execute(
+            "INSERT OR IGNORE INTO projects (id, name, content_repo, visibility) "
+            "VALUES ('secret', 'Secret', 'secret-content', 'gated')"
+        )
+        db.conn().execute(
+            "INSERT OR IGNORE INTO collections (id, project_id, type, subfolder, initial_state, visibility, name) "
+            "VALUES ('secret', 'secret', 'document', '', 'super-draft', 'gated', 'Secret')"
+        )
+        provision_user_row(user_id=4, login="bob", role="contributor")
+        sign_in_as(client, user_id=4, gitea_login="bob", display_name="Bob",
+                   role="contributor", email="bob@test")
+        r = client.post("/api/projects/secret/rfcs/propose", json={
+            "title": "X", "slug": "x", "pitch": "p", "tags": [],
+        })
+        assert r.status_code == 404

backend/tests/test_project_scoped_serving.py

@@ -0,0 +1,74 @@
+"""§22.4 (Plan B) — per-project RFC serving. A second project's corpus renders
+under its own slug namespace via /api/projects/{pid}/rfcs[/{slug}], isolated
+from the default project and gated by §22.5 visibility."""
+from __future__ import annotations
+
+from fastapi.testclient import TestClient
+
+from test_propose_vertical import (  # noqa: F401
+    app_with_fake_gitea, tmp_env, provision_user_row, sign_in_as,
+)
+
+
+def _add_project(pid, name, vis="public"):
+    # §22 three-tier: a project + its default collection (keyed by the project
+    # id in tests, so default_collection_id(pid) == pid).
+    from app import db
+    db.conn().execute(
+        "INSERT OR IGNORE INTO projects (id, name, content_repo, visibility) VALUES (?, ?, ?, ?)",
+        (pid, name, pid + "-content", vis),
+    )
+    db.conn().execute(
+        "INSERT OR IGNORE INTO collections (id, project_id, type, subfolder, initial_state, visibility, name) "
+        "VALUES (?, ?, 'document', '', 'super-draft', ?, ?)",
+        (pid, pid, vis, name),
+    )
+
+
+def _add_rfc(slug, title, pid, state="active"):
+    from app import db
+    # entries key by the project's default collection (id == pid in these tests)
+    db.conn().execute(
+        "INSERT INTO cached_rfcs (slug, title, state, collection_id) VALUES (?, ?, ?, ?)",
+        (slug, title, state, pid),
+    )
+
+
+def test_catalog_scoped_to_one_project(app_with_fake_gitea):
+    app, _ = app_with_fake_gitea
+    with TestClient(app) as client:
+        _add_project("ecomm", "Ecomm")
+        _add_rfc("intro", "Default Intro", "default")
+        _add_rfc("intro", "Ecomm Intro", "ecomm")
+        _add_rfc("only-ecomm", "Ecomm Only", "ecomm")
+
+        d = client.get("/api/projects/default/rfcs").json()["items"]
+        e = client.get("/api/projects/ecomm/rfcs").json()["items"]
+        d_slugs = {i["slug"] for i in d}
+        e_slugs = {i["slug"] for i in e}
+        assert "intro" in d_slugs and "only-ecomm" not in d_slugs
+        assert {"intro", "only-ecomm"} <= e_slugs
+
+
+def test_entry_is_isolated_by_project(app_with_fake_gitea):
+    app, _ = app_with_fake_gitea
+    with TestClient(app) as client:
+        _add_project("ecomm", "Ecomm")
+        _add_rfc("intro", "Default Intro", "default")
+        _add_rfc("intro", "Ecomm Intro", "ecomm")
+        _add_rfc("only-ecomm", "Ecomm Only", "ecomm")
+
+        assert client.get("/api/projects/default/rfcs/intro").json()["title"] == "Default Intro"
+        assert client.get("/api/projects/ecomm/rfcs/intro").json()["title"] == "Ecomm Intro"
+        # a slug that exists only in ecomm 404s under default
+        assert client.get("/api/projects/ecomm/rfcs/only-ecomm").status_code == 200
+        assert client.get("/api/projects/default/rfcs/only-ecomm").status_code == 404
+
+
+def test_gated_project_catalog_404s_for_anon(app_with_fake_gitea):
+    app, _ = app_with_fake_gitea
+    with TestClient(app) as client:
+        _add_project("secret", "Secret", vis="gated")
+        _add_rfc("hush", "Hush", "secret")
+        assert client.get("/api/projects/secret/rfcs").status_code == 404
+        assert client.get("/api/projects/secret/rfcs/hush").status_code == 404

backend/tests/test_propose_vertical.py

@@ -55,6 +55,24 @@ class FakeGitea:
         self._pr_counter = 0
         self._commit_counter = 0
         self._seed_repo("wiggleverse", "meta")
+        # §22 M3: the deployment's project registry. Startup refresh_registry
+        # reads projects.yaml here; the single 'default' project's content_repo
+        # points back at the seeded meta repo so the corpus mirror is unchanged.
+        self._seed_repo("wiggleverse", "registry")
+        self.files[("wiggleverse", "registry", "main", "projects.yaml")] = {
+            "content": (
+                "deployment:\n"
+                "  name: Test Deployment\n"
+                "  tagline: A test deployment\n"
+                "projects:\n"
+                "  - id: default\n"
+                "    name: Test Deployment\n"
+                "    type: document\n"
+                "    content_repo: meta\n"
+                "    visibility: public\n"
+            ),
+            "sha": "regsha0001",
+        }
 
     def _seed_repo(self, owner, repo):
         self.branches[(owner, repo)] = {"main": {"sha": "initial", "ts": "2026-05-23T00:00:00Z"}}
@@ -72,6 +90,28 @@ class FakeGitea:
         self._commit_counter += 1
         return f"sha{self._commit_counter:04d}"
 
+    def _dir_listing(self, owner, repo, ref, dirpath):
+        """Children directly under `dirpath` on (owner, repo, ref): files as
+        `type: file` and immediate subdirectories as `type: dir` (the shape real
+        Gitea returns for a contents listing)."""
+        prefix = (dirpath.rstrip("/") + "/") if dirpath else ""
+        files: dict[str, dict] = {}
+        dirs: set[str] = set()
+        for (o, r, br, p), data in self.files.items():
+            if (o, r, br) != (owner, repo, ref) or not p.startswith(prefix):
+                continue
+            rest = p[len(prefix):]
+            if "/" in rest:
+                dirs.add(rest.split("/", 1)[0])
+            elif rest:
+                files[p] = data
+        children = [{"name": n, "path": prefix + n, "type": "dir"} for n in sorted(dirs)]
+        children += [
+            {"name": p.rsplit("/", 1)[-1], "path": p, "type": "file", "sha": d["sha"]}
+            for p, d in sorted(files.items())
+        ]
+        return children
+
     def _enrich_pr(self, owner: str, repo: str, pr: dict) -> dict:
         """Return the PR with mergeability fields filled in.
 
@@ -209,6 +249,16 @@ class FakeGitea:
             }
             return httpx.Response(201, json={"name": new})
 
+        # GET /repos/{owner}/{repo}/contents (root listing, empty path). §22 S2:
+        # the registry mirror walks the content-repo root for collection
+        # subfolders, so the simulator models a root directory listing that
+        # surfaces both file and `dir` children.
+        m_root = re.fullmatch(r"/repos/([^/]+)/([^/]+)/contents/?", path)
+        if method == "GET" and m_root:
+            owner, repo = m_root.groups()
+            ref = request.url.params.get("ref", "main")
+            return httpx.Response(200, json=self._dir_listing(owner, repo, ref, ""))
+
         # GET /repos/{owner}/{repo}/contents/{path}?ref=...
         m = re.fullmatch(r"/repos/([^/]+)/([^/]+)/contents/(.+)", path)
         if method == "GET" and m:
@@ -224,17 +274,8 @@ class FakeGitea:
                     "sha": f["sha"],
                     "content": base64.b64encode(f["content"].encode()).decode(),
                 })
-            # Directory listing
-            prefix = fpath.rstrip("/") + "/"
-            children = []
-            for (o, r, br, p), data in self.files.items():
-                if (o, r, br) == (owner, repo, ref) and p.startswith(prefix) and "/" not in p[len(prefix):]:
-                    children.append({
-                        "name": p.rsplit("/", 1)[-1],
-                        "path": p,
-                        "type": "file",
-                        "sha": data["sha"],
-                    })
+            # Directory listing — both file and subdir children.
+            children = self._dir_listing(owner, repo, ref, fpath)
             if children:
                 return httpx.Response(200, json=children)
             return httpx.Response(404, json={"message": "not found"})
@@ -431,7 +472,7 @@ def tmp_env(monkeypatch):
         "GITEA_BOT_USER": "rfc-bot",
         "GITEA_BOT_TOKEN": "bot-token",
         "GITEA_ORG": "wiggleverse",
-        "META_REPO": "meta",
+        "REGISTRY_REPO": "registry",
         "OAUTH_CLIENT_ID": "cid",
         "OAUTH_CLIENT_SECRET": "csec",
         "APP_URL": "http://localhost:8000",
@@ -444,6 +485,18 @@ def tmp_env(monkeypatch):
         # the dev-bypass path monkeypatch `RFC_APP_INSECURE_WEBHOOKS=1`.
         "GITEA_WEBHOOK_SECRET": "test-webhook-secret-for-signature-verification",
         "ENABLED_MODELS": "claude",
+        # v0.27.0 (audit 0026 M4): the session cookie now defaults to
+        # Secure. The TestClient talks plain http://testserver, so a
+        # Secure cookie is never sent back and every authenticated flow
+        # would fail. Tests opt out explicitly, exactly as a dev box on
+        # plain http does.
+        "SESSION_COOKIE_SECURE": "false",
+        # v0.27.0 (audit 0026 M5): the bounce webhook fails closed (503)
+        # when its secret is unset. Tests exercise the legacy behavioral
+        # path via the documented dev opt-in, mirroring the
+        # RFC_APP_INSECURE_WEBHOOKS bypass above. Tests that assert the
+        # fail-closed default delenv this key themselves.
+        "RFC_APP_INSECURE_BOUNCE_WEBHOOK": "1",
     }
     for k, v in env.items():
         monkeypatch.setenv(k, v)
@@ -565,6 +618,97 @@ def test_propose_to_super_draft_vertical(app_with_fake_gitea):
         assert ("merge_proposal", "ben") in kinds
 
 
+def test_merged_idea_pr_with_deleted_branch_clears_proposal(app_with_fake_gitea):
+    """Regression: a merged idea PR whose branch was deleted must not
+    linger as a 'pending idea' ghost.
+
+    Found via the ROADMAP #35 operator authoring lane: merging an idea
+    PR from the CLI with `--delete-branch` makes Gitea report the PR's
+    `head.ref` as the synthetic `refs/pull/<N>/head` sentinel instead of
+    `propose/<slug>`. `refresh_meta_pulls` derives the slug from the
+    branch name, so the sentinel parsed to slug=None, the row was skipped,
+    and `cached_prs.state` stayed frozen at 'open' — leaving the entry
+    showing as BOTH a super-draft (cached_rfcs reconciled off the push)
+    AND a pending idea (cached_prs never updated). The fix recovers the
+    original branch name from the already-stored cached_prs row.
+
+    The web UX never tripped this because it leaves the branch in place
+    (the repo's default_delete_branch_after_merge is false).
+
+    The bug only manifests on an out-of-band merge (the PR merged +
+    branch deleted directly in Gitea, with the in-app merge endpoint never
+    reconciling the row while the branch still existed) -- which is exactly
+    what the #35 CLI lane does. An in-app merge reconciles cached_prs to
+    'merged' before the branch is gone, so it never trips this; the test
+    therefore drives the Gitea state directly to reproduce the CLI path.
+    """
+    from fastapi.testclient import TestClient
+    from app import db, cache, gitea as gitea_mod
+    from app.config import load_config
+
+    app, fake = app_with_fake_gitea
+
+    with TestClient(app) as client:
+        provision_user_row(user_id=2, login="alice", role="contributor")
+        sign_in_as(client, user_id=2, gitea_login="alice", display_name="Alice", role="contributor", email="alice@test")
+        r = client.post("/api/rfcs/propose", json={
+            "title": "Informed Consent",
+            "slug": "informed-consent",
+            "pitch": "A first-class definition of consent in OHM.",
+            "tags": [],
+        })
+        assert r.status_code == 200, r.text
+        pr_number = r.json()["pr_number"]
+
+        # The proposal is cached as an open idea PR.
+        items = client.get("/api/proposals").json()["items"]
+        assert any(i["pr_number"] == pr_number for i in items)
+
+        # Out-of-band CLI merge (ROADMAP #35 lane): the PR is merged AND
+        # its branch deleted directly in Gitea, WITHOUT the in-app merge
+        # endpoint ever running. So cached_prs still says state='open' and
+        # Gitea now reports the merged PR's head.ref as the sentinel. This
+        # is the exact state `rfc-authoring.sh pr-merge --delete-branch`
+        # leaves behind.
+        for pr in fake.pulls[("wiggleverse", "meta")]:
+            if pr["number"] == pr_number:
+                # land the file on main (the push side already reconciles
+                # cached_rfcs into a super-draft via the webhook/sweep)
+                for (o, rp, br, p), data in list(fake.files.items()):
+                    if (o, rp, br) == ("wiggleverse", "meta", "propose/informed-consent"):
+                        fake.files[("wiggleverse", "meta", "main", p)] = dict(data)
+                pr["state"] = "closed"
+                pr["merged"] = True
+                pr["merged_at"] = "2026-05-29T12:13:00Z"
+                pr["closed_at"] = "2026-05-29T12:13:00Z"
+                pr["merge_commit_sha"] = fake._next_sha()
+                pr["head"]["ref"] = f"refs/pull/{pr_number}/head"
+        fake.branches[("wiggleverse", "meta")].pop("propose/informed-consent", None)
+
+        # The reconcile sweep runs (a later webhook, or the 5-min safety net).
+        import asyncio
+        cfg = load_config()
+        gclient = gitea_mod.Gitea(cfg)
+        asyncio.run(cache.refresh_meta_repo(cfg, gclient))
+        asyncio.run(cache.refresh_meta_pulls(cfg, gclient))
+
+        # The bug: this used to still list informed-consent (frozen 'open'
+        # row, slug unparseable from the sentinel). The fix recovers the
+        # stored branch name, so the row reconciles to merged and the ghost
+        # is gone.
+        assert client.get("/api/proposals").json()["items"] == []
+
+        # And the cached_prs row is correctly merged, not a frozen 'open'.
+        row = db.conn().execute(
+            "SELECT state FROM cached_prs WHERE pr_number = ?", (pr_number,)
+        ).fetchone()
+        assert row["state"] == "merged", f"expected merged, got {row['state']}"
+
+        # The super-draft itself is unaffected — still in the catalog.
+        items = client.get("/api/rfcs").json()["items"]
+        assert any(i["slug"] == "informed-consent" and i["state"] == "super-draft" for i in items)
+
+
 def test_slug_uniqueness_enforced(app_with_fake_gitea):
     from fastapi.testclient import TestClient
     app, _fake = app_with_fake_gitea

backend/tests/test_registry.py

@@ -0,0 +1,106 @@
+"""§22.2 registry parse + apply: validation, type-immutability, upsert."""
+from __future__ import annotations
+
+import tempfile
+from pathlib import Path
+
+import pytest
+
+from app import db, registry
+from app.config import Config
+
+
+def _db():
+    cfg = Config(
+        gitea_url="x", gitea_bot_user="x", gitea_bot_token="x", gitea_org="x",
+        registry_repo="registry", oauth_client_id="x",
+        oauth_client_secret="x", app_url="x", secret_key="x",
+        database_path=Path(tempfile.mkdtemp(prefix="reg-")) / "t.db",
+        owner_gitea_login="x", webhook_secret="x",
+    )
+    db.run_migrations(cfg)
+    if db._CONN is not None:
+        db._CONN.close()
+        db._CONN = None
+    db.init(cfg)
+    return cfg
+
+
+VALID = """
+deployment:
+  name: Open Human Model
+  tagline: A model of human flourishing
+projects:
+  - id: default
+    name: Open Human Model
+    type: document
+    content_repo: meta
+    visibility: public
+"""
+
+
+def test_parse_valid_registry():
+    doc = registry.parse_registry(VALID)
+    assert doc.deployment_name == "Open Human Model"
+    assert doc.deployment_tagline == "A model of human flourishing"
+    assert len(doc.projects) == 1
+    p = doc.projects[0]
+    assert (p.id, p.type, p.content_repo, p.visibility) == ("default", "document", "meta", "public")
+    assert p.initial_state == "super-draft"
+
+
+def test_parse_initial_state_defaults_per_type():
+    doc = registry.parse_registry(
+        "projects:\n  - {id: a, name: A, type: bdd, content_repo: a}\n"
+    )
+    assert doc.projects[0].initial_state == "active"  # bdd default
+
+
+@pytest.mark.parametrize("bad,msg", [
+    ("projects: []\n", "at least one"),
+    ("projects:\n  - just-a-string\n", "must be a mapping"),
+    ("projects:\n  - {id: 'Bad Slug', name: A, type: document, content_repo: a}\n", "valid slug"),
+    ("projects:\n  - {id: a, name: A, type: nope, content_repo: a}\n", "invalid type"),
+    ("projects:\n  - {id: a, name: A, type: document}\n", "content_repo"),
+    ("projects:\n  - {id: a, name: A, type: document, content_repo: a, visibility: x}\n", "visibility"),
+    ("projects:\n  - {id: a, name: A, type: document, content_repo: a}\n  - {id: a, name: B, type: document, content_repo: b}\n", "duplicate"),
+])
+def test_parse_rejects_invalid(bad, msg):
+    with pytest.raises(registry.RegistryError) as e:
+        registry.parse_registry(bad)
+    assert msg in str(e.value)
+
+
+def test_apply_upserts_projects_and_deployment():
+    _db()
+    doc = registry.parse_registry(VALID)
+    registry.apply_registry(doc, registry_sha="regsha1", default_id="default")
+    # §22 three-tier: the project carries the grouping-tier fields; the
+    # per-corpus type/initial_state live on its default collection.
+    prow = db.conn().execute(
+        "SELECT name, content_repo, visibility, registry_sha FROM projects WHERE id='default'"
+    ).fetchone()
+    assert prow["name"] == "Open Human Model"
+    assert prow["content_repo"] == "meta"
+    assert prow["registry_sha"] == "regsha1"
+    crow = db.conn().execute(
+        "SELECT type, initial_state FROM collections WHERE id='default'"
+    ).fetchone()
+    assert crow["type"] == "document"
+    assert crow["initial_state"] == "super-draft"
+    drow = db.conn().execute("SELECT name, tagline FROM deployment WHERE id=1").fetchone()
+    assert drow["name"] == "Open Human Model"
+    assert drow["tagline"] == "A model of human flourishing"
+
+
+def test_apply_rejects_type_change_on_existing_project():
+    _db()
+    registry.apply_registry(registry.parse_registry(VALID), "s1", default_id="default")
+    changed = VALID.replace("type: document", "type: specification")
+    registry.apply_registry(registry.parse_registry(changed), "s2", default_id="default")  # skipped
+    # §22.4a immutable type — now enforced on the collection.
+    t = db.conn().execute("SELECT type FROM collections WHERE id='default'").fetchone()["type"]
+    assert t == "document"  # immutable — unchanged
+    # The deployment row IS still advanced even though the type change was skipped.
+    drow = db.conn().execute("SELECT registry_sha FROM deployment WHERE id=1").fetchone()
+    assert drow["registry_sha"] == "s2"

backend/tests/test_registry_wiring.py

@@ -0,0 +1,54 @@
+"""Startup mirrors the registry; the registry webhook re-mirrors it."""
+from __future__ import annotations
+
+from fastapi.testclient import TestClient
+
+from test_propose_vertical import app_with_fake_gitea, tmp_env  # noqa: F401
+
+
+def test_startup_mirrors_registry_into_projects_and_deployment(app_with_fake_gitea):
+    from app import db
+
+    app, _ = app_with_fake_gitea
+    with TestClient(app):
+        prow = db.conn().execute(
+            "SELECT content_repo FROM projects WHERE id='default'"
+        ).fetchone()
+        assert prow["content_repo"] == "meta"   # from the registry, not META_REPO
+        # §22 three-tier: type now lives on the default collection.
+        crow = db.conn().execute(
+            "SELECT type FROM collections WHERE id='default'"
+        ).fetchone()
+        assert crow["type"] == "document"
+        drow = db.conn().execute("SELECT name FROM deployment WHERE id=1").fetchone()
+        assert drow["name"]  # deployment name mirrored from the registry
+
+
+def test_registry_webhook_remirrors(app_with_fake_gitea):
+    import hashlib
+    import hmac
+    import json as _json
+
+    app, fake = app_with_fake_gitea
+    with TestClient(app) as client:
+        from app import db
+        new_yaml = (
+            "deployment:\n  name: OHM\n  tagline: Edited tagline\n"
+            "projects:\n  - id: default\n    name: OHM\n    type: document\n"
+            "    content_repo: meta\n    visibility: public\n"
+        )
+        fake.files[("wiggleverse", "registry", "main", "projects.yaml")] = {
+            "content": new_yaml, "sha": "regsha2",
+        }
+        body = _json.dumps({"repository": {"full_name": "wiggleverse/registry"}}).encode()
+        secret = "test-webhook-secret-for-signature-verification"
+        sig = hmac.new(secret.encode(), body, hashlib.sha256).hexdigest()
+        r = client.post(
+            "/api/webhooks/gitea",
+            content=body,
+            headers={"X-Gitea-Event": "push", "X-Gitea-Signature": sig,
+                     "Content-Type": "application/json"},
+        )
+        assert r.status_code == 200
+        tagline = db.conn().execute("SELECT tagline FROM deployment WHERE id=1").fetchone()["tagline"]
+        assert tagline == "Edited tagline"

backend/tests/test_restamp_default_project.py

@@ -0,0 +1,69 @@
+"""§22.13 step 1 — the bootstrap-id re-stamp: 'default' → the configured
+DEFAULT_PROJECT_ID. §22 three-tier (S1): the entry-corpus tables key on
+collection_id now, so the re-stamp renames the *project grain* — the
+`collections.project_id` link and the denormalised project_id tags — while the
+entries stay in their collection. The stale 'default' projects row is dropped,
+the composite FKs stay intact, and it is idempotent."""
+from __future__ import annotations
+
+import tempfile
+from pathlib import Path
+
+import app.db as db
+from app import projects
+
+
+class _Cfg:
+    def __init__(self, path, default_id):
+        self.database_path = path
+        self.default_project_id = default_id
+
+
+def _setup(monkeypatch, default_id="ohm"):
+    path = str(Path(tempfile.mkdtemp()) / "t.db")
+    cfg = _Cfg(path, default_id)
+    db.run_migrations(cfg)  # seeds the bootstrap 'default' project + its default collection
+    monkeypatch.setattr(db, "_CONN", db.connect(path))
+    conn = db.conn()
+    # A registry-mirrored 'ohm' project coexists with the bootstrap pre-restamp.
+    conn.execute("INSERT OR IGNORE INTO projects (id,name,content_repo,visibility) "
+                 "VALUES ('ohm','Open Human Model','ohm-content','public')")
+    conn.execute("INSERT INTO users (id,gitea_login,display_name,role) VALUES (1,'a','A','contributor')")
+    # Entry data lives in the default collection (id='default'); the entry grain
+    # is the collection and does not move on a re-stamp.
+    conn.execute("INSERT INTO cached_rfcs (slug,title,state,collection_id) VALUES ('human','Human','active','default')")
+    conn.execute("INSERT INTO rfc_collaborators (rfc_slug,user_id,role_in_rfc,collection_id) "
+                 "VALUES ('human',1,'contributor','default')")
+    conn.execute("INSERT INTO stars (user_id,rfc_slug,collection_id) VALUES (1,'human','default')")
+    return cfg, conn
+
+
+def test_restamp_moves_project_grain_and_drops_bootstrap_row(monkeypatch):
+    cfg, conn = _setup(monkeypatch, default_id="ohm")
+    projects.restamp_default_project(cfg)
+    # The project grain (the collection's parent link) re-stamps to 'ohm'.
+    assert conn.execute("SELECT COUNT(*) c FROM collections WHERE project_id='default'").fetchone()["c"] == 0
+    assert conn.execute("SELECT project_id FROM collections WHERE id='default'").fetchone()["project_id"] == "ohm"
+    # Entries stay in their collection — the collection_id is unchanged.
+    assert conn.execute("SELECT collection_id FROM cached_rfcs WHERE slug='human'").fetchone()["collection_id"] == "default"
+    assert conn.execute("SELECT collection_id FROM rfc_collaborators WHERE rfc_slug='human'").fetchone()["collection_id"] == "default"
+    # stale bootstrap projects row removed; 'ohm' remains
+    assert conn.execute("SELECT 1 FROM projects WHERE id='default'").fetchone() is None
+    assert conn.execute("SELECT 1 FROM projects WHERE id='ohm'").fetchone() is not None
+    # FK integrity intact after the rename
+    assert conn.execute("PRAGMA foreign_key_check").fetchall() == []
+
+
+def test_restamp_is_idempotent(monkeypatch):
+    cfg, conn = _setup(monkeypatch, default_id="ohm")
+    projects.restamp_default_project(cfg)
+    projects.restamp_default_project(cfg)  # second call: no bootstrap rows left → no-op
+    assert conn.execute("SELECT project_id FROM collections WHERE id='default'").fetchone()["project_id"] == "ohm"
+    assert conn.execute("SELECT COUNT(*) c FROM cached_rfcs WHERE collection_id='default'").fetchone()["c"] == 1
+
+
+def test_restamp_noop_when_default_id_unchanged(monkeypatch):
+    cfg, conn = _setup(monkeypatch, default_id="")  # resolves to 'default'
+    projects.restamp_default_project(cfg)
+    # nothing renamed; the default collection still belongs to the bootstrap project
+    assert conn.execute("SELECT project_id FROM collections WHERE id='default'").fetchone()["project_id"] == "default"

backend/tests/test_retire_vertical.py

@@ -0,0 +1,257 @@
+"""End-to-end integration tests for the §13.7 retire (soft-delete) flow.
+
+Retire is an in-place frontmatter flip on the meta entry (state →
+`retired`) committed via an auto-merged PR — the same machinery as
+graduation, reused. The distinguishing rules under test:
+
+  * Authority (§3.1): RFC owners (frontmatter) and site `owner`-role
+    holders may retire; app admins may NOT. Un-retire is site-owners-only.
+  * Visibility (§13.7): a retired entry drops out of the catalog
+    (`GET /api/rfcs`), and `GET /api/rfcs/<slug>` 404s for everyone except
+    a site owner (so the un-retire affordance has a surface).
+  * Reversibility: a site owner can un-retire, restoring the prior state
+    (and keeping the integer id intact); an RFC owner cannot.
+
+These walk against the in-process FakeGitea from test_propose_vertical.py,
+reusing the super-draft seed + sync graduation seam from the graduation
+suite.
+"""
+from __future__ import annotations
+
+import json as _json
+
+from test_propose_vertical import (  # noqa: F401
+    FakeGitea,
+    app_with_fake_gitea,
+    grant_rfc_collaborator,
+    provision_user_row,
+    sign_in_as,
+    tmp_env,
+)
+from test_super_draft_vertical import seed_super_draft  # noqa: F401
+from test_graduation_vertical import PITCH, seed_owned_super_draft  # noqa: F401
+
+
+def _catalog_slugs(client) -> set[str]:
+    return {i["slug"] for i in client.get("/api/rfcs").json()["items"]}
+
+
+def test_rfc_owner_can_retire_and_entry_leaves_every_surface(app_with_fake_gitea):
+    """An RFC owner (frontmatter, role contributor) retires their own
+    super-draft. The entry flips to `retired`, drops out of the catalog,
+    and `GET /api/rfcs/<slug>` 404s for them (they are not a site owner)."""
+    from fastapi.testclient import TestClient
+    from app import db, entry as entry_mod
+
+    app, fake = app_with_fake_gitea
+    with TestClient(app) as client:
+        provision_user_row(user_id=2, login="carol", role="contributor")
+        seed_owned_super_draft(fake, slug="ohm", title="OHM",
+                               pitch=PITCH, owners=["carol"], arbiters=["carol"])
+        sign_in_as(client, user_id=2, gitea_login="carol",
+                   display_name="Carol", role="contributor")
+
+        assert "ohm" in _catalog_slugs(client)
+
+        r = client.post("/api/rfcs/ohm/retire")
+        assert r.status_code == 200, r.text
+        assert r.json()["state"] == "retired"
+
+        # Meta entry on main: state retired, body + fields kept.
+        meta = entry_mod.parse(
+            fake.files[("wiggleverse", "meta", "main", "rfcs/ohm.md")]["content"]
+        )
+        assert meta.state == "retired"
+        assert "carol" in meta.owners
+
+        # Cache flipped; gone from the catalog.
+        cached = db.conn().execute(
+            "SELECT state FROM cached_rfcs WHERE slug = 'ohm'"
+        ).fetchone()
+        assert cached["state"] == "retired"
+        assert "ohm" not in _catalog_slugs(client)
+
+        # The RFC owner is NOT a site owner → 404 on the entry read.
+        assert client.get("/api/rfcs/ohm").status_code == 404
+
+        # Audit row records the prior state for un-retire.
+        row = db.conn().execute(
+            "SELECT details FROM actions WHERE rfc_slug='ohm' AND action_kind='retire' ORDER BY id DESC LIMIT 1"
+        ).fetchone()
+        assert row is not None
+        assert _json.loads(row["details"])["prior_state"] == "super-draft"
+
+
+def test_site_owner_sees_retired_entry_but_admin_and_others_404(app_with_fake_gitea):
+    """`GET /api/rfcs/<slug>` for a retired entry: site owner gets 200
+    (so the un-retire UI has a surface); an admin, a non-owner contributor,
+    and an anonymous viewer all get 404."""
+    from fastapi.testclient import TestClient
+
+    app, fake = app_with_fake_gitea
+    with TestClient(app) as client:
+        provision_user_row(user_id=1, login="ben", role="owner")
+        provision_user_row(user_id=2, login="carol", role="contributor")
+        provision_user_row(user_id=3, login="dave", role="admin")
+        seed_owned_super_draft(fake, slug="ohm", title="OHM",
+                               pitch=PITCH, owners=["carol"])
+
+        sign_in_as(client, user_id=2, gitea_login="carol",
+                   display_name="Carol", role="contributor")
+        assert client.post("/api/rfcs/ohm/retire").status_code == 200
+
+        # Site owner: 200.
+        sign_in_as(client, user_id=1, gitea_login="ben",
+                   display_name="Ben", role="owner")
+        r = client.get("/api/rfcs/ohm")
+        assert r.status_code == 200, r.text
+        assert r.json()["state"] == "retired"
+
+        # Admin (not site owner): 404.
+        sign_in_as(client, user_id=3, gitea_login="dave",
+                   display_name="Dave", role="admin")
+        assert client.get("/api/rfcs/ohm").status_code == 404
+
+        # Non-owner contributor: 404.
+        provision_user_row(user_id=4, login="erin", role="contributor")
+        sign_in_as(client, user_id=4, gitea_login="erin",
+                   display_name="Erin", role="contributor")
+        assert client.get("/api/rfcs/ohm").status_code == 404
+
+
+def test_admin_cannot_retire(app_with_fake_gitea):
+    """§3.1: retire authority excludes app admins. An admin who is not an
+    RFC owner gets 403 — the one lifecycle action where admin authority
+    does not apply."""
+    from fastapi.testclient import TestClient
+
+    app, fake = app_with_fake_gitea
+    with TestClient(app) as client:
+        provision_user_row(user_id=3, login="dave", role="admin")
+        seed_owned_super_draft(fake, slug="ohm", title="OHM",
+                               pitch=PITCH, owners=["carol"])
+        sign_in_as(client, user_id=3, gitea_login="dave",
+                   display_name="Dave", role="admin")
+        r = client.post("/api/rfcs/ohm/retire")
+        assert r.status_code == 403, r.text
+
+
+def test_non_owner_contributor_cannot_retire(app_with_fake_gitea):
+    """A signed-in contributor who is not an RFC owner gets 403."""
+    from fastapi.testclient import TestClient
+
+    app, fake = app_with_fake_gitea
+    with TestClient(app) as client:
+        provision_user_row(user_id=4, login="erin", role="contributor")
+        seed_owned_super_draft(fake, slug="ohm", title="OHM",
+                               pitch=PITCH, owners=["carol"])
+        sign_in_as(client, user_id=4, gitea_login="erin",
+                   display_name="Erin", role="contributor")
+        assert client.post("/api/rfcs/ohm/retire").status_code == 403
+
+
+def test_site_owner_can_retire_active_and_unretire_restores_active_with_id(app_with_fake_gitea):
+    """Round-trip on an active RFC: graduate (with a number) → retire →
+    un-retire. The integer id survives, and un-retire restores `active`."""
+    from fastapi.testclient import TestClient
+    from app import db, entry as entry_mod
+
+    app, fake = app_with_fake_gitea
+    with TestClient(app) as client:
+        provision_user_row(user_id=1, login="ben", role="owner")
+        seed_owned_super_draft(fake, slug="ohm", title="OHM",
+                               pitch=PITCH, owners=["ben"], arbiters=["ben"])
+        sign_in_as(client, user_id=1, gitea_login="ben",
+                   display_name="Ben", role="owner", email="ben@test")
+
+        # Graduate with a number.
+        assert client.post("/api/rfcs/ohm/graduate?_sync=1",
+                           json={"rfc_id": "RFC-0042", "owners": ["ben"]}).status_code == 200
+
+        # Retire (site owner).
+        assert client.post("/api/rfcs/ohm/retire").json()["state"] == "retired"
+        assert "ohm" not in _catalog_slugs(client)
+
+        # Un-retire (site owner) restores active, id intact.
+        r = client.post("/api/rfcs/ohm/unretire")
+        assert r.status_code == 200, r.text
+        assert r.json()["state"] == "active"
+
+        meta = entry_mod.parse(
+            fake.files[("wiggleverse", "meta", "main", "rfcs/ohm.md")]["content"]
+        )
+        assert meta.state == "active"
+        assert meta.id == "RFC-0042"
+
+        cached = db.conn().execute(
+            "SELECT state, rfc_id FROM cached_rfcs WHERE slug = 'ohm'"
+        ).fetchone()
+        assert cached["state"] == "active"
+        assert cached["rfc_id"] == "RFC-0042"
+        assert "ohm" in _catalog_slugs(client)
+
+
+def test_rfc_owner_cannot_unretire(app_with_fake_gitea):
+    """Un-retire is site-owner-only: an RFC owner who could retire cannot
+    bring it back (the soft-delete is recoverable only by the operator)."""
+    from fastapi.testclient import TestClient
+
+    app, fake = app_with_fake_gitea
+    with TestClient(app) as client:
+        provision_user_row(user_id=2, login="carol", role="contributor")
+        seed_owned_super_draft(fake, slug="ohm", title="OHM",
+                               pitch=PITCH, owners=["carol"])
+        sign_in_as(client, user_id=2, gitea_login="carol",
+                   display_name="Carol", role="contributor")
+        assert client.post("/api/rfcs/ohm/retire").status_code == 200
+        # Same RFC owner tries to un-retire → 403.
+        assert client.post("/api/rfcs/ohm/unretire").status_code == 403
+
+
+def test_admin_retired_list_is_site_owner_only(app_with_fake_gitea):
+    """GET /api/admin/retired-rfcs lists retired entries for a site owner;
+    an admin (who lacks un-retire authority) gets 403."""
+    from fastapi.testclient import TestClient
+
+    app, fake = app_with_fake_gitea
+    with TestClient(app) as client:
+        provision_user_row(user_id=1, login="ben", role="owner")
+        provision_user_row(user_id=2, login="carol", role="contributor")
+        provision_user_row(user_id=3, login="dave", role="admin")
+        seed_owned_super_draft(fake, slug="ohm", title="OHM",
+                               pitch=PITCH, owners=["carol"])
+        sign_in_as(client, user_id=2, gitea_login="carol",
+                   display_name="Carol", role="contributor")
+        assert client.post("/api/rfcs/ohm/retire").status_code == 200
+
+        # Admin: 403.
+        sign_in_as(client, user_id=3, gitea_login="dave",
+                   display_name="Dave", role="admin")
+        assert client.get("/api/admin/retired-rfcs").status_code == 403
+
+        # Site owner: 200, sees ohm with its restore target.
+        sign_in_as(client, user_id=1, gitea_login="ben",
+                   display_name="Ben", role="owner")
+        r = client.get("/api/admin/retired-rfcs")
+        assert r.status_code == 200, r.text
+        items = r.json()["items"]
+        ohm = next(i for i in items if i["slug"] == "ohm")
+        assert ohm["restores_to"] == "super-draft"
+
+
+def test_retired_entry_refuses_discussion_reads(app_with_fake_gitea):
+    """A retired entry refuses content reads of every shape (§13.7) — the
+    discussion/branch surfaces 404/409 rather than serve a soft-deleted RFC."""
+    from fastapi.testclient import TestClient
+
+    app, fake = app_with_fake_gitea
+    with TestClient(app) as client:
+        provision_user_row(user_id=2, login="carol", role="contributor")
+        seed_owned_super_draft(fake, slug="ohm", title="OHM",
+                               pitch=PITCH, owners=["carol"])
+        sign_in_as(client, user_id=2, gitea_login="carol",
+                   display_name="Carol", role="contributor")
+        assert client.post("/api/rfcs/ohm/retire").status_code == 200
+
+        # The /main branch surface no longer serves it.
+        assert client.get("/api/rfcs/ohm/main").status_code in (404, 409)

backend/tests/test_rfc_links_vertical.py

@@ -94,6 +94,44 @@ def test_longest_match_wins():
     assert out[-1]["label"] == "Open Human Model"
 
 
+def test_pending_term_emits_contribute_segment():
+    # Part 3: a super-draft match is an `rfc-pending` segment carrying the
+    # owner display name, not a plain link.
+    idx = rfc_links.LinkIndex([
+        rfc_links.Term(key="open human model", kind="pending",
+                       slug="open-human-model", title="Open Human Model", owner="Alice"),
+    ])
+    out = idx.segment("see Open Human Model please")
+    assert out[1] == {
+        "type": "rfc-pending", "slug": "open-human-model",
+        "label": "Open Human Model", "title": "Open Human Model", "owner": "Alice",
+    }
+
+
+def test_candidate_term_emits_create_segment():
+    # Part 2: a candidate term carries its canonical spelling for the
+    # propose pre-fill; no slug (no RFC exists yet).
+    idx = rfc_links.LinkIndex([
+        rfc_links.Term(key="memory model", kind="candidate", term="Memory Model"),
+    ])
+    out = idx.segment("the memory model is unspecified")
+    assert out[1] == {"type": "rfc-candidate", "label": "memory model", "term": "Memory Model"}
+
+
+def test_kind_precedence_active_beats_pending_beats_candidate():
+    # All three buckets contribute the same key; the highest-precedence
+    # kind (active) must win at the position.
+    key = "open human model"
+    idx = rfc_links.LinkIndex([
+        rfc_links.Term(key=key, kind="candidate", term="Open Human Model"),
+        rfc_links.Term(key=key, kind="pending", slug="ohm-draft", title="Open Human Model", owner="A"),
+        rfc_links.Term(key=key, kind="active", slug="open-human-model", title="Open Human Model"),
+    ])
+    out = idx.segment("the Open Human Model")
+    assert out[-1]["type"] == "rfc"
+    assert out[-1]["slug"] == "open-human-model"
+
+
 def test_keys_for_gating():
     keys = lambda **kw: set(rfc_links._keys_for(**kw))
     # rfc_id always contributes.

backend/tests/test_s1_collection_grain_vertical.py

@@ -0,0 +1,78 @@
+"""@S1 acceptance — the collection grain exists (invisible default) and N=1 is
+unchanged.
+
+Part C scenarios C3.7 (single-collection project skips the directory) and C3.8
+(single-project deployment skips the directory) are the client-side redirect
+contract asserted in the frontend; this module asserts the backend N=1
+invariants behind the slice: every entry keys on a real collection_id, the
+shipped project-scoped serving still resolves through the default collection,
+and the legacy /rfc/<slug> URL 308-redirects through /c/<default>/.
+
+Binding: docs/design/2026-06-05-three-tier-projects-collections.md §A.6 / Part E.
+"""
+from __future__ import annotations
+
+from fastapi.testclient import TestClient
+
+from test_propose_vertical import (  # noqa: F401
+    app_with_fake_gitea, tmp_env, provision_user_row, sign_in_as,
+)
+
+
+def _seed_entry(slug, title, collection_id="default", state="active"):
+    from app import db
+    db.conn().execute(
+        "INSERT INTO cached_rfcs (slug, title, state, collection_id) VALUES (?, ?, ?, ?)",
+        (slug, title, state, collection_id),
+    )
+
+
+def test_s1_migration_seeds_one_default_collection_for_the_default_project(app_with_fake_gitea):
+    from app import db
+    app, _ = app_with_fake_gitea
+    with TestClient(app):
+        row = db.conn().execute(
+            "SELECT id FROM collections WHERE project_id = 'default'"
+        ).fetchall()
+        assert len(row) == 1
+        assert row[0]["id"] == "default"
+
+
+def test_s1_entry_served_under_default_collection(app_with_fake_gitea):
+    """N=1 unchanged: an entry is keyed by collection_id under the hood and the
+    shipped project-scoped serving endpoint still resolves it."""
+    from app import db
+    app, _ = app_with_fake_gitea
+    with TestClient(app) as client:
+        _seed_entry("human", "Human")
+        # the row carries a real collection grain (the default collection)
+        cid = db.conn().execute(
+            "SELECT collection_id FROM cached_rfcs WHERE slug='human'"
+        ).fetchone()["collection_id"]
+        assert cid == "default"
+        # project-scoped serving (collection = default) still returns it
+        r = client.get("/api/projects/default/rfcs/human")
+        assert r.status_code == 200, r.text
+        assert r.json()["slug"] == "human"
+        # and it appears in the project catalog
+        slugs = [i["slug"] for i in client.get("/api/projects/default/rfcs").json()["items"]]
+        assert "human" in slugs
+
+
+def test_s1_legacy_rfc_url_redirects_through_collection(app_with_fake_gitea):
+    """The shipped /rfc/<slug> now 308s through the default collection segment."""
+    app, _ = app_with_fake_gitea
+    with TestClient(app) as client:
+        r = client.get("/rfc/human", follow_redirects=False)
+        assert r.status_code == 308
+        assert r.headers["location"] == "/p/default/c/default/e/human"
+
+
+def test_s1_deployment_reports_single_project(app_with_fake_gitea):
+    """C3.8 precondition: the N=1 deployment reports exactly one visible project
+    and its default id (the frontend uses this to skip the directory)."""
+    app, _ = app_with_fake_gitea
+    with TestClient(app) as client:
+        body = client.get("/api/deployment").json()
+        assert body["default_project_id"] == "default"
+        assert [p["id"] for p in body["projects"]] == ["default"]

backend/tests/test_s3_scope_roles_vertical.py

@@ -0,0 +1,287 @@
+"""Slice S3 — scope-role enforcement + collection-grain visibility (@S3).
+
+The acceptance gate for S3 is "every Part C.1 scenario passes" (the design doc
+docs/design/2026-06-05-three-tier-projects-collections.md, §C.1, tagged @S3) plus
+the operator's S3 visibility requirements (a collection settable public/hidden;
+hidden = visible to project/global scope contributors but not the public; a
+collection's visibility may be set only as strict or stricter than its project).
+
+The §B.2 resolver folds four layers — global → project → collection → per-entry —
+most-permissively, with no negative override. The scenarios below are exercised
+directly against the resolver/gate helpers, and the visibility ones additionally
+through the HTTP surface.
+
+Background (C.1): a deployment with a project "ohm" owning collections "model"
+(document) and "features" (bdd); a second project "acme" with collection
+"specs". Plus a hidden ("gated") collection "secret" under ohm for the
+hidden-from-public scenarios.
+"""
+from __future__ import annotations
+
+from fastapi.testclient import TestClient
+
+from test_propose_vertical import (  # noqa: F401 — fixtures land via import
+    app_with_fake_gitea,
+    provision_user_row,
+    sign_in_as,
+    tmp_env,
+)
+
+
+# ---------------------------------------------------------------------------
+# Helpers
+# ---------------------------------------------------------------------------
+
+
+def _su(user_id: int, login: str, role: str = "contributor", *, state: str = "granted"):
+    from app import auth
+
+    return auth.SessionUser(
+        user_id=user_id, gitea_id=user_id, gitea_login=login,
+        display_name=login.capitalize(), email=f"{login}@test", avatar_url="",
+        role=role, permission_state=state,
+    )
+
+
+def _project(pid: str, visibility: str = "public", content_repo: str = "meta") -> None:
+    from app import db
+
+    db.conn().execute(
+        "INSERT OR REPLACE INTO projects (id, name, content_repo, visibility, updated_at) "
+        "VALUES (?, ?, ?, ?, datetime('now'))",
+        (pid, pid.capitalize(), content_repo, visibility),
+    )
+
+
+def _collection(cid: str, project_id: str, *, ctype: str = "document",
+                visibility: str = "public", subfolder: str | None = None) -> None:
+    from app import db
+
+    db.conn().execute(
+        "INSERT OR REPLACE INTO collections "
+        "(id, project_id, type, subfolder, initial_state, visibility, name, created_at, updated_at) "
+        "VALUES (?, ?, ?, ?, 'super-draft', ?, ?, datetime('now'), datetime('now'))",
+        (cid, project_id, ctype, subfolder if subfolder is not None else cid,
+         visibility, cid.capitalize()),
+    )
+
+
+def _grant(scope_type: str, scope_id: str, user_id: int, role: str) -> None:
+    from app import db
+
+    db.conn().execute(
+        "INSERT OR REPLACE INTO memberships (scope_type, scope_id, user_id, role) "
+        "VALUES (?, ?, ?, ?)",
+        (scope_type, scope_id, user_id, role),
+    )
+
+
+def _seed_world() -> None:
+    """The C.1 background plus a hidden collection and a second project."""
+    _project("ohm", "public")
+    _collection("ohm", "ohm", subfolder="")          # ohm's structural default
+    _collection("model", "ohm", ctype="document")
+    _collection("features", "ohm", ctype="bdd")
+    _collection("secret", "ohm", visibility="gated")  # hidden from public
+    _project("acme", "public")
+    _collection("specs", "acme", ctype="specification")
+    # the cast
+    for uid, login in [(1, "ada"), (2, "ben"), (3, "cleo"), (4, "dan"),
+                       (5, "eve"), (6, "fay"), (7, "gil"), (8, "hana")]:
+        provision_user_row(user_id=uid, login=login, role="contributor")
+    _grant("collection", "model", 1, "contributor")   # ada
+    _grant("project", "ohm", 2, "contributor")         # ben
+    _grant("global", "*", 3, "contributor")            # cleo
+    _grant("collection", "features", 4, "owner")       # dan
+    _grant("project", "ohm", 5, "owner")               # eve
+    _grant("collection", "model", 6, "contributor")    # fay (+ project owner below)
+    _grant("project", "ohm", 6, "owner")               # fay
+    _grant("project", "ohm", 7, "contributor")         # gil
+    # hana (8): no grant.
+
+
+# ---------------------------------------------------------------------------
+# C.1 — role usage: inheritance and the most-permissive union
+# ---------------------------------------------------------------------------
+
+
+def test_c1_1_collection_contributor_proposes_only_in_that_collection(app_with_fake_gitea):
+    from app import auth
+    app, _ = app_with_fake_gitea
+    with TestClient(app):
+        _seed_world()
+        ada = _su(1, "ada")
+        # may submit a new entry in ohm/model
+        assert auth.can_contribute_in_collection(ada, "model") is True
+        # ohm/features is read-only and propose is not offered
+        assert auth.can_read_collection(ada, "features") is True
+        assert auth.can_contribute_in_collection(ada, "features") is False
+
+
+def test_c1_2_project_contributor_proposes_in_every_collection(app_with_fake_gitea):
+    from app import auth
+    app, _ = app_with_fake_gitea
+    with TestClient(app):
+        _seed_world()
+        ben = _su(2, "ben")
+        assert auth.can_contribute_in_collection(ben, "model") is True
+        assert auth.can_contribute_in_collection(ben, "features") is True
+        # a collection added later is writable with no new grant
+        _collection("roadmap", "ohm", ctype="document")
+        assert auth.can_contribute_in_collection(ben, "roadmap") is True
+
+
+def test_c1_3_global_contributor_proposes_everywhere(app_with_fake_gitea):
+    from app import auth
+    app, _ = app_with_fake_gitea
+    with TestClient(app):
+        _seed_world()
+        cleo = _su(3, "cleo")
+        assert auth.can_contribute_in_collection(cleo, "model") is True
+        assert auth.can_contribute_in_collection(cleo, "specs") is True  # acme
+
+
+def test_c1_4_collection_owner_administers_one_collection_only(app_with_fake_gitea):
+    from app import auth
+    app, _ = app_with_fake_gitea
+    with TestClient(app):
+        _seed_world()
+        dan = _su(4, "dan")
+        # graduate / mark-reviewed / manage membership in ohm/features
+        assert auth.is_collection_superuser(dan, "features") is True
+        # but not change ohm project settings
+        assert auth.is_project_superuser(dan, "ohm") is False
+        assert auth.can_create_collection(dan, "ohm") is False
+        # and not act on entries in ohm/model
+        assert auth.is_collection_superuser(dan, "model") is False
+        assert auth.can_contribute_in_collection(dan, "model") is False
+
+
+def test_c1_5_project_owner_administers_all_collections_and_creates_more(app_with_fake_gitea):
+    from app import auth
+    app, _ = app_with_fake_gitea
+    with TestClient(app):
+        _seed_world()
+        eve = _su(5, "eve")
+        assert auth.is_collection_superuser(eve, "model") is True
+        assert auth.is_collection_superuser(eve, "features") is True
+        assert auth.is_project_superuser(eve, "ohm") is True       # edit project settings
+        assert auth.can_create_collection(eve, "ohm") is True      # create a new collection
+
+
+def test_c1_6_most_permissive_union_higher_grant_wins(app_with_fake_gitea):
+    from app import auth
+    app, _ = app_with_fake_gitea
+    with TestClient(app):
+        _seed_world()
+        fay = _su(6, "fay")
+        # collection RFC Contributor at model + project Owner at ohm → acts as Owner in model
+        assert auth.effective_scope_role(fay, "model") == "owner"
+        assert auth.is_collection_superuser(fay, "model") is True
+
+
+def test_c1_7_no_negative_override(app_with_fake_gitea):
+    from app import auth, db
+    app, _ = app_with_fake_gitea
+    with TestClient(app):
+        _seed_world()
+        gil = _su(7, "gil")
+        # gil can propose in ohm/model via the project grant…
+        assert auth.can_contribute_in_collection(gil, "model") is True
+        # …and there is no collection-scope row to remove at model while keeping
+        # the project grant (a child cannot subtract a parent grant).
+        row = db.conn().execute(
+            "SELECT 1 FROM memberships WHERE user_id = 7 AND scope_type = 'collection' AND scope_id = 'model'"
+        ).fetchone()
+        assert row is None
+
+
+def test_c1_8_granted_account_no_role_sees_only_public(app_with_fake_gitea):
+    from app import auth
+    app, _ = app_with_fake_gitea
+    with TestClient(app):
+        _seed_world()
+        hana = _su(8, "hana")
+        # may read public collections
+        assert auth.can_read_collection(hana, "model") is True
+        # but is not offered the propose action anywhere (no scope role; the
+        # grandfathered baseline covers only the N=1 `default` collection)
+        assert auth.can_contribute_in_collection(hana, "model") is False
+        assert auth.can_contribute_in_collection(hana, "features") is False
+        assert auth.can_contribute_in_collection(hana, "specs") is False
+        # gated (hidden) collections do not appear for her
+        assert auth.can_read_collection(hana, "secret") is False
+
+
+# ---------------------------------------------------------------------------
+# Collection-grain visibility — the operator's S3 requirements
+# ---------------------------------------------------------------------------
+
+
+def test_hidden_collection_invisible_to_public_visible_to_scope_holder(app_with_fake_gitea):
+    """A gated collection is omitted from the directory and 404s on read for the
+    public, yet is listed + readable for a scope-role contributor."""
+    app, _ = app_with_fake_gitea
+    with TestClient(app) as client:
+        _seed_world()
+        # anonymous: the gated 'secret' collection is not listed, and 404s.
+        listed = {c["id"] for c in client.get("/api/projects/ohm/collections").json()["items"]}
+        assert "secret" not in listed
+        assert "model" in listed  # public ones still listed
+        assert client.get("/api/projects/ohm/collections/secret").status_code == 404
+        assert client.get("/api/projects/ohm/collections/secret/rfcs").status_code == 404
+
+        # ben (project contributor) sees and reads it.
+        sign_in_as(client, user_id=2, gitea_login="ben", display_name="Ben", role="contributor")
+        listed2 = {c["id"] for c in client.get("/api/projects/ohm/collections").json()["items"]}
+        assert "secret" in listed2
+        assert client.get("/api/projects/ohm/collections/secret").status_code == 200
+        assert client.get("/api/projects/ohm/collections/secret/rfcs").status_code == 200
+
+        # hana (granted, no role) is back to the public view.
+        sign_in_as(client, user_id=8, gitea_login="hana", display_name="Hana", role="contributor")
+        listed3 = {c["id"] for c in client.get("/api/projects/ohm/collections").json()["items"]}
+        assert "secret" not in listed3
+        assert client.get("/api/projects/ohm/collections/secret").status_code == 404
+
+
+def test_collection_visibility_strictness_validated_at_create(app_with_fake_gitea):
+    """A collection may be created only as strict or stricter than its project;
+    a looser request is refused (422). On a gated project, a 'public' collection
+    is rejected."""
+    app, _ = app_with_fake_gitea
+    with TestClient(app) as client:
+        _project("locked", "gated")
+        _collection("locked", "locked", subfolder="", visibility="gated")
+        # eve is a deployment owner here to clear the create-authority gate;
+        # the strictness check fires regardless.
+        provision_user_row(user_id=9, login="root", role="owner")
+        sign_in_as(client, user_id=9, gitea_login="root", display_name="Root", role="owner")
+        r = client.post("/api/projects/locked/collections", json={
+            "collection_id": "wideopen", "type": "document", "visibility": "public",
+        })
+        assert r.status_code == 422, r.text
+        assert "looser" in r.json()["detail"]
+
+
+def test_create_collection_allowed_for_project_owner_not_plain_contributor(app_with_fake_gitea):
+    """§B.1: a project-scope Owner may create a collection; a plain granted
+    contributor with no project/global grant may not (403)."""
+    app, fake = app_with_fake_gitea
+    with TestClient(app) as client:
+        _seed_world()
+        # gil is only a project *contributor* on ohm — per §B.1 a project-scope
+        # contributor CAN create collections (the project-level create
+        # affordance). A collection-scope grant cannot.
+        sign_in_as(client, user_id=7, gitea_login="gil", display_name="Gil", role="contributor")
+        r_ok = client.post("/api/projects/ohm/collections", json={
+            "collection_id": "fromgil", "type": "document", "visibility": "public",
+        })
+        assert r_ok.status_code in (200, 502), r_ok.text  # past the authz gate
+
+        # ada holds only a *collection*-scope grant (at model) — no create right.
+        sign_in_as(client, user_id=1, gitea_login="ada", display_name="Ada", role="contributor")
+        r_no = client.post("/api/projects/ohm/collections", json={
+            "collection_id": "fromada", "type": "document", "visibility": "public",
+        })
+        assert r_no.status_code == 403, r_no.text

backend/tests/test_s4_invitations_vertical.py

@@ -0,0 +1,331 @@
+"""Slice S4 — invitation surfaces + role-aware empty states (@S4).
+
+The acceptance gate for S4 is "every Part C.2 invitation scenario passes" (the
+design doc docs/design/2026-06-05-three-tier-projects-collections.md, §C.2,
+tagged @S4), plus the capability flags that drive the C.3 (@S4) role-aware
+empty states.
+
+An Owner grants {owner, contributor} at a scope their reach covers — the
+project, or a single collection within it — to an existing account looked up by
+email. The grant writes a `memberships` row immediately and §15-notifies the
+grantee (no accept round-trip). Reach is bounded by the inviter's Owner reach;
+re-granting at a broader scope supersedes the narrower row; a `pending`
+deployment account's grant is recorded but confers no write.
+
+Background (C.2): project "ohm" owns collections "model" (document) and
+"features" (bdd). eve is project Owner of ohm; dan is collection Owner of
+features only; ben is a project Contributor of ohm. ivy / jo / jet are
+grantees; kim is a pending deployment account.
+"""
+from __future__ import annotations
+
+from fastapi.testclient import TestClient
+
+from test_propose_vertical import (  # noqa: F401 — fixtures land via import
+    app_with_fake_gitea,
+    provision_user_row,
+    sign_in_as,
+    tmp_env,
+)
+
+
+# ---------------------------------------------------------------------------
+# Helpers (mirror the S3 vertical's world-builders)
+# ---------------------------------------------------------------------------
+
+
+def _su(user_id: int, login: str, role: str = "contributor", *, state: str = "granted"):
+    from app import auth
+
+    return auth.SessionUser(
+        user_id=user_id, gitea_id=user_id, gitea_login=login,
+        display_name=login.capitalize(), email=f"{login}@test", avatar_url="",
+        role=role, permission_state=state,
+    )
+
+
+def _project(pid: str, visibility: str = "public", content_repo: str = "meta") -> None:
+    from app import db
+
+    db.conn().execute(
+        "INSERT OR REPLACE INTO projects (id, name, content_repo, visibility, updated_at) "
+        "VALUES (?, ?, ?, ?, datetime('now'))",
+        (pid, pid.capitalize(), content_repo, visibility),
+    )
+
+
+def _collection(cid: str, project_id: str, *, ctype: str = "document",
+                visibility: str = "public", subfolder: str | None = None) -> None:
+    from app import db
+
+    db.conn().execute(
+        "INSERT OR REPLACE INTO collections "
+        "(id, project_id, type, subfolder, initial_state, visibility, name, created_at, updated_at) "
+        "VALUES (?, ?, ?, ?, 'super-draft', ?, ?, datetime('now'), datetime('now'))",
+        (cid, project_id, ctype, subfolder if subfolder is not None else cid,
+         visibility, cid.capitalize()),
+    )
+
+
+def _grant(scope_type: str, scope_id: str, user_id: int, role: str) -> None:
+    from app import db
+
+    db.conn().execute(
+        "INSERT OR REPLACE INTO memberships (scope_type, scope_id, user_id, role) "
+        "VALUES (?, ?, ?, ?)",
+        (scope_type, scope_id, user_id, role),
+    )
+
+
+def _membership(user_id: int):
+    """The set of (scope_type, scope_id, role) rows a user holds."""
+    from app import db
+
+    rows = db.conn().execute(
+        "SELECT scope_type, scope_id, role FROM memberships WHERE user_id = ?",
+        (user_id,),
+    ).fetchall()
+    return {(r["scope_type"], r["scope_id"], r["role"]) for r in rows}
+
+
+def _seed_world() -> None:
+    _project("ohm", "public")
+    _collection("model", "ohm", ctype="document")
+    _collection("features", "ohm", ctype="bdd")
+    # the cast
+    provision_user_row(user_id=2, login="ben", role="contributor")
+    provision_user_row(user_id=4, login="dan", role="contributor")
+    provision_user_row(user_id=5, login="eve", role="contributor")
+    provision_user_row(user_id=10, login="ivy", role="contributor")
+    provision_user_row(user_id=11, login="jo", role="contributor")
+    provision_user_row(user_id=12, login="jet", role="contributor")
+    provision_user_row(user_id=13, login="kim", role="contributor")
+    _grant("project", "ohm", 5, "owner")          # eve — project Owner
+    _grant("collection", "features", 4, "owner")  # dan — collection Owner only
+    _grant("project", "ohm", 2, "contributor")    # ben — project Contributor
+    # kim is a pending deployment account.
+    from app import db
+    db.conn().execute(
+        "UPDATE users SET permission_state = 'pending' WHERE id = 13"
+    )
+
+
+def _login_eve(client) -> None:
+    sign_in_as(client, user_id=5, gitea_login="eve", display_name="Eve", role="contributor")
+
+
+# ---------------------------------------------------------------------------
+# C.2 — invitation: who may invite whom, at which scope
+# ---------------------------------------------------------------------------
+
+
+def test_c2_1_project_owner_invites_at_project_scope(app_with_fake_gitea):
+    """A project Owner grants at project scope; the grant covers every
+    collection, and the grantee is §15-notified naming the project and role."""
+    from app import auth
+    app, _ = app_with_fake_gitea
+    with TestClient(app) as client:
+        _seed_world()
+        _login_eve(client)
+        r = client.post("/api/projects/ohm/members",
+                        json={"email": "ivy@test", "role": "contributor"})
+        assert r.status_code == 200, r.text
+        # a membership row is written at scope project "ohm"
+        assert ("project", "ohm", "contributor") in _membership(10)
+        # ivy may propose in every collection of "ohm"
+        ivy = _su(10, "ivy")
+        assert auth.can_contribute_in_collection(ivy, "model") is True
+        assert auth.can_contribute_in_collection(ivy, "features") is True
+        # ivy receives a §15 notification naming the project and role
+        sign_in_as(client, user_id=10, gitea_login="ivy", display_name="Ivy", role="contributor")
+        inbox = client.get("/api/notifications").json()["items"]
+        granted = [n for n in inbox if n["event_kind"] == "scope_role_granted"]
+        assert granted, inbox
+        assert "Ohm" in granted[0]["summary"]
+        assert "RFC Contributor" in granted[0]["summary"]
+
+
+def test_c2_2_owner_invites_at_specific_collection(app_with_fake_gitea):
+    """A grant at a single collection scope reaches that collection only."""
+    from app import auth
+    app, _ = app_with_fake_gitea
+    with TestClient(app) as client:
+        _seed_world()
+        _login_eve(client)
+        r = client.post("/api/projects/ohm/members",
+                        json={"email": "jo@test", "role": "contributor",
+                              "collection_id": "features"})
+        assert r.status_code == 200, r.text
+        assert ("collection", "features", "contributor") in _membership(11)
+        jo = _su(11, "jo")
+        assert auth.can_contribute_in_collection(jo, "features") is True
+        assert auth.can_contribute_in_collection(jo, "model") is False
+
+
+def test_c2_3_invitation_reach_bounded_by_inviter_scope(app_with_fake_gitea):
+    """A collection Owner may invite within that collection, but is not offered
+    (is refused) the control to invite at the project or globally."""
+    app, _ = app_with_fake_gitea
+    with TestClient(app) as client:
+        _seed_world()
+        # dan is Owner at collection "features" only.
+        sign_in_as(client, user_id=4, gitea_login="dan", display_name="Dan", role="contributor")
+        # may grant at his collection
+        ok = client.post("/api/projects/ohm/members",
+                         json={"email": "ivy@test", "role": "contributor",
+                               "collection_id": "features"})
+        assert ok.status_code == 200, ok.text
+        # but not at the project scope
+        no = client.post("/api/projects/ohm/members",
+                         json={"email": "ivy@test", "role": "contributor"})
+        assert no.status_code == 403, no.text
+        # the capability flags the UI reads agree: no project invite, yes collection
+        proj = client.get("/api/projects/ohm/collections").json()["viewer"]
+        assert proj["can_invite"] is False
+        col = client.get("/api/projects/ohm/collections/features").json()["viewer"]
+        assert col["can_invite"] is True
+
+
+def test_c2_4_contributors_do_not_manage_membership(app_with_fake_gitea):
+    """An RFC Contributor (project- or collection-scoped) holds no invite
+    capability and the grant endpoints refuse them."""
+    app, _ = app_with_fake_gitea
+    with TestClient(app) as client:
+        _seed_world()
+        # ben is a project *Contributor* on ohm.
+        sign_in_as(client, user_id=2, gitea_login="ben", display_name="Ben", role="contributor")
+        no_proj = client.post("/api/projects/ohm/members",
+                              json={"email": "ivy@test", "role": "contributor"})
+        assert no_proj.status_code == 403, no_proj.text
+        no_col = client.post("/api/projects/ohm/members",
+                             json={"email": "ivy@test", "role": "contributor",
+                                   "collection_id": "features"})
+        assert no_col.status_code == 403, no_col.text
+        # no invite control surfaced anywhere
+        assert client.get("/api/projects/ohm/collections").json()["viewer"]["can_invite"] is False
+        assert client.get("/api/projects/ohm/collections/features").json()["viewer"]["can_invite"] is False
+
+
+def test_c2_5_no_grant_at_parent_revoke_at_child_option(app_with_fake_gitea):
+    """The grant surface offers only role + scope (project or one collection);
+    there is no way to grant at the project yet carve out a child collection —
+    a project grant reaches every collection, full stop."""
+    from app import auth
+    app, _ = app_with_fake_gitea
+    with TestClient(app) as client:
+        _seed_world()
+        _login_eve(client)
+        # the only knobs are role and an optional single collection_id; an
+        # "exclude" field has no effect (it is not part of the contract).
+        r = client.post("/api/projects/ohm/members",
+                        json={"email": "ivy@test", "role": "contributor",
+                              "exclude_collection_id": "features"})
+        assert r.status_code == 200, r.text
+        # the project grant still reaches the supposedly-excluded collection
+        ivy = _su(10, "ivy")
+        assert auth.can_contribute_in_collection(ivy, "features") is True
+
+
+def test_c2_6_broader_scope_supersedes_narrower(app_with_fake_gitea):
+    """Re-granting at a broader scope removes the subsumed narrower row; the
+    grantee holds the role across the whole project."""
+    from app import auth
+    app, _ = app_with_fake_gitea
+    with TestClient(app) as client:
+        _seed_world()
+        _grant("collection", "features", 12, "contributor")  # jet starts narrow
+        _login_eve(client)
+        r = client.post("/api/projects/ohm/members",
+                        json={"email": "jet@test", "role": "contributor"})
+        assert r.status_code == 200, r.text
+        rows = _membership(12)
+        # the project grant is present…
+        assert ("project", "ohm", "contributor") in rows
+        # …and the redundant collection-scope row is gone (subsumed)
+        assert ("collection", "features", "contributor") not in rows
+        jet = _su(12, "jet")
+        assert auth.can_contribute_in_collection(jet, "model") is True
+        assert auth.can_contribute_in_collection(jet, "features") is True
+
+
+def test_c2_6b_narrower_stronger_role_is_not_subtracted(app_with_fake_gitea):
+    """No negative override: a child Owner grant survives a parent Contributor
+    grant (the stronger collection role is kept)."""
+    app, _ = app_with_fake_gitea
+    with TestClient(app) as client:
+        _seed_world()
+        _grant("collection", "features", 12, "owner")  # jet is collection Owner
+        _login_eve(client)
+        r = client.post("/api/projects/ohm/members",
+                        json={"email": "jet@test", "role": "contributor"})
+        assert r.status_code == 200, r.text
+        rows = _membership(12)
+        assert ("project", "ohm", "contributor") in rows
+        # the stronger collection-Owner row is NOT pruned by a weaker project grant
+        assert ("collection", "features", "owner") in rows
+
+
+def test_c2_7_pending_account_grant_confers_no_write(app_with_fake_gitea):
+    """A grant to a pending deployment account is recorded but confers no write
+    until the account is granted at the deployment (§6)."""
+    from app import auth
+    app, _ = app_with_fake_gitea
+    with TestClient(app) as client:
+        _seed_world()
+        _login_eve(client)
+        r = client.post("/api/projects/ohm/members",
+                        json={"email": "kim@test", "role": "contributor"})
+        assert r.status_code == 200, r.text
+        assert r.json()["pending"] is True
+        # the grant row is recorded…
+        assert ("project", "ohm", "contributor") in _membership(13)
+        # …but confers no write while pending (the §6 admission floor)
+        kim = _su(13, "kim", state="pending")
+        assert auth.effective_scope_role(kim, "model") is None
+        assert auth.can_contribute_in_collection(kim, "model") is False
+
+
+# ---------------------------------------------------------------------------
+# C.3 (@S4) — the capability flags behind the role-aware empty states
+# ---------------------------------------------------------------------------
+
+
+def test_c3_3_project_owner_sees_create_first_collection_capability(app_with_fake_gitea):
+    """C3.3: a project Owner landing on an empty project may create a
+    collection — the flag the 'Create your first collection' CTA reads."""
+    app, _ = app_with_fake_gitea
+    with TestClient(app) as client:
+        _seed_world()
+        _login_eve(client)
+        caps = client.get("/api/projects/ohm/collections").json()["viewer"]
+        assert caps["can_create_collection"] is True
+        assert caps["role"] == "owner"
+
+
+def test_c3_4_contributor_without_create_rights_has_no_create_capability(app_with_fake_gitea):
+    """C3.4: a contributor whose only grant is at a collection elsewhere has no
+    create-collection capability — the empty directory shows no create action."""
+    app, _ = app_with_fake_gitea
+    with TestClient(app) as client:
+        _seed_world()
+        # dan holds only a collection-scope grant (features); no project create right.
+        sign_in_as(client, user_id=4, gitea_login="dan", display_name="Dan", role="contributor")
+        caps = client.get("/api/projects/ohm/collections").json()["viewer"]
+        assert caps["can_create_collection"] is False
+
+
+def test_c3_5_collection_contributor_sees_propose_first_capability(app_with_fake_gitea):
+    """C3.5: a collection contributor landing on an empty collection may propose
+    — the flag the 'Propose the first entry' CTA reads; an anonymous reader may
+    not (the sign-in prompt path, already shipped in S2)."""
+    app, _ = app_with_fake_gitea
+    with TestClient(app) as client:
+        _seed_world()
+        _grant("collection", "model", 10, "contributor")  # ivy contributes in model
+        sign_in_as(client, user_id=10, gitea_login="ivy", display_name="Ivy", role="contributor")
+        caps = client.get("/api/projects/ohm/collections/model").json()["viewer"]
+        assert caps["can_contribute"] is True
+        # anonymous reader: no propose capability
+        client.cookies.clear()
+        caps_anon = client.get("/api/projects/ohm/collections/model").json()["viewer"]
+        assert caps_anon["can_contribute"] is False

backend/tests/test_s6_collection_models_vertical.py

@@ -0,0 +1,141 @@
+"""§22.12 S6 — per-collection model universe.
+
+A collection's `.collection.yaml` may carry an `enabled_models` list that
+NARROWS its project's universe, which in turn narrows the deployment
+ENABLED_MODELS. The resolution chain (extending §6.6/§6.7) is:
+
+    funder ∩ per-entry models ∩ collection universe ∩ project universe
+                                            (operator providers = the ceiling)
+
+These tests prove (1) the manifest parser reads `enabled_models`, (2) the
+mirror stores it on the collection row, (3) the resolver narrows the base
+universe by project then collection, with absent = inherit and [] = opt-out,
+and (4) the collection API surfaces the collection's own narrowing.
+"""
+from __future__ import annotations
+
+import json
+
+from fastapi.testclient import TestClient
+
+from app import db, models_resolver, registry
+from test_propose_vertical import (  # noqa: F401
+    app_with_fake_gitea, provision_user_row, sign_in_as, tmp_env,
+)
+from test_rfc_view_vertical import FakeProvider, seed_active_rfc  # noqa: F401
+
+
+def _install_two_providers(app) -> None:
+    app.state.providers.clear()
+    app.state.providers["claude"] = FakeProvider("TITLE: A\nDESCRIPTION: B")
+    app.state.providers["gemini"] = FakeProvider("TITLE: G\nDESCRIPTION: H")
+
+
+def _set_project_models(project_id: str, models) -> None:
+    cfg = {} if models is None else {"enabled_models": models}
+    db.conn().execute(
+        "UPDATE projects SET config_json = ? WHERE id = ?",
+        (json.dumps(cfg), project_id),
+    )
+
+
+def _set_collection_models(collection_id: str, models) -> None:
+    cfg = None if models is None else json.dumps({"enabled_models": models})
+    db.conn().execute(
+        "UPDATE collections SET config_json = ? WHERE id = ?",
+        (cfg, collection_id),
+    )
+
+
+# ── manifest parsing ───────────────────────────────────────────────────────
+
+
+def test_manifest_parses_enabled_models_into_config():
+    ce = registry.parse_collection_manifest(
+        "type: bdd\nname: Features\nenabled_models: [claude, gemini]\n"
+    )
+    assert ce.config.get("enabled_models") == ["claude", "gemini"]
+
+
+def test_manifest_without_enabled_models_has_no_key():
+    ce = registry.parse_collection_manifest("type: document\nname: Model\n")
+    assert "enabled_models" not in ce.config
+
+
+def test_manifest_rejects_non_list_enabled_models():
+    import pytest
+    with pytest.raises(registry.RegistryError):
+        registry.parse_collection_manifest("type: bdd\nenabled_models: claude\n")
+
+
+# ── resolver narrowing (the §22.12 chain) ──────────────────────────────────
+
+
+def test_resolver_inherits_operator_universe_when_no_scope_narrowing(app_with_fake_gitea):
+    app, fake = app_with_fake_gitea
+    with TestClient(app):
+        seed_active_rfc(fake, slug="ohm", title="OHM", body="x")
+        _install_two_providers(app)
+        # No project/collection narrowing → full operator universe.
+        resolved = models_resolver.resolve_models_for_rfc("ohm", app.state.providers)
+        assert resolved == ["claude", "gemini"]
+
+
+def test_resolver_narrows_by_project_universe(app_with_fake_gitea):
+    app, fake = app_with_fake_gitea
+    with TestClient(app):
+        seed_active_rfc(fake, slug="ohm", title="OHM", body="x")
+        _install_two_providers(app)
+        _set_project_models("default", ["gemini"])
+        resolved = models_resolver.resolve_models_for_rfc("ohm", app.state.providers)
+        assert resolved == ["gemini"]
+
+
+def test_resolver_collection_narrows_within_project(app_with_fake_gitea):
+    app, fake = app_with_fake_gitea
+    with TestClient(app):
+        seed_active_rfc(fake, slug="ohm", title="OHM", body="x")
+        _install_two_providers(app)
+        # Project allows both; the collection narrows to claude only.
+        _set_project_models("default", ["claude", "gemini"])
+        _set_collection_models("default", ["claude"])
+        resolved = models_resolver.resolve_models_for_rfc("ohm", app.state.providers)
+        assert resolved == ["claude"]
+
+
+def test_resolver_collection_empty_list_opts_out(app_with_fake_gitea):
+    app, fake = app_with_fake_gitea
+    with TestClient(app):
+        seed_active_rfc(fake, slug="ohm", title="OHM", body="x")
+        _install_two_providers(app)
+        _set_collection_models("default", [])  # opt this collection out of AI
+        resolved = models_resolver.resolve_models_for_rfc("ohm", app.state.providers)
+        assert resolved == []
+
+
+def test_resolver_collection_cannot_widen_project(app_with_fake_gitea):
+    app, fake = app_with_fake_gitea
+    with TestClient(app):
+        seed_active_rfc(fake, slug="ohm", title="OHM", body="x")
+        _install_two_providers(app)
+        # Project restricts to gemini; the collection naming claude+gemini
+        # cannot re-add claude (narrowing only).
+        _set_project_models("default", ["gemini"])
+        _set_collection_models("default", ["claude", "gemini"])
+        resolved = models_resolver.resolve_models_for_rfc("ohm", app.state.providers)
+        assert resolved == ["gemini"]
+
+
+# ── API surfacing ──────────────────────────────────────────────────────────
+
+
+def test_collection_api_surfaces_enabled_models(app_with_fake_gitea):
+    app, fake = app_with_fake_gitea
+    with TestClient(app) as client:
+        provision_user_row(user_id=1, login="ben", role="owner")
+        sign_in_as(client, user_id=1, gitea_login="ben", display_name="Ben",
+                   role="owner", email="ben@test")
+        _set_collection_models("default", ["claude"])
+        r = client.get("/api/projects/default/collections/default")
+        assert r.status_code == 200, r.text
+        assert r.json().get("enabled_models") == ["claude"]

backend/tests/test_s6_entry_noun_vertical.py

@@ -0,0 +1,48 @@
+"""§22.4a S6 — the type-driven entry noun.
+
+The displayed noun for an entry is a framework concept keyed on the
+collection's immutable type: document→"RFC", specification→"Spec", bdd→"Feature".
+The chrome reads it from the API rather than hardcoding "RFC", so the propose
+CTA + entry chrome name entries correctly per collection type with no
+per-deployment config.
+"""
+from __future__ import annotations
+
+from fastapi.testclient import TestClient
+
+from app import collections, db
+from test_propose_vertical import (  # noqa: F401
+    app_with_fake_gitea, provision_user_row, sign_in_as, tmp_env,
+)
+
+
+def test_entry_noun_map():
+    assert collections.entry_noun("document") == "RFC"
+    assert collections.entry_noun("specification") == "Spec"
+    assert collections.entry_noun("bdd") == "Feature"
+    # An unknown/future type falls back to the generic noun, never label-less.
+    assert collections.entry_noun("mystery") == "RFC"
+
+
+def test_collection_api_surfaces_entry_noun(app_with_fake_gitea):
+    app, _ = app_with_fake_gitea
+    with TestClient(app) as client:
+        provision_user_row(user_id=1, login="ben", role="owner")
+        sign_in_as(client, user_id=1, gitea_login="ben", display_name="Ben",
+                   role="owner", email="ben@test")
+        # Flip the default collection to a bdd type and confirm the noun follows.
+        db.conn().execute("UPDATE collections SET type='bdd' WHERE id='default'")
+        r = client.get("/api/projects/default/collections/default")
+        assert r.status_code == 200, r.text
+        assert r.json()["entry_noun"] == "Feature"
+
+
+def test_directory_items_carry_entry_noun(app_with_fake_gitea):
+    app, _ = app_with_fake_gitea
+    with TestClient(app) as client:
+        db.conn().execute("UPDATE projects SET visibility='public' WHERE id='default'")
+        db.conn().execute("UPDATE collections SET type='specification' WHERE id='default'")
+        r = client.get("/api/deployment")
+        assert r.status_code == 200, r.text
+        item = next(p for p in r.json()["projects"] if p["id"] == "default")
+        assert item["entry_noun"] == "Spec"

backend/tests/test_s6_two_project_multicollection.py

@@ -0,0 +1,90 @@
+"""§22 S6 — two-project / multi-collection integrative pass.
+
+Proves the S6 surface holds across a deployment with two projects, each owning
+distinct collections, with the new per-collection knobs (§22.12 enabled_models,
+§22.4a type noun) resolving independently per collection — no cross-project or
+cross-collection bleed.
+
+Slug note: the resolver is slug-keyed, so this test uses distinct slugs across
+collections (the documented limitation — same-slug-across-collections model
+resolution is part of the broader collection-id-threading follow-up).
+"""
+from __future__ import annotations
+
+import json
+
+from fastapi.testclient import TestClient
+
+from app import collections, db, models_resolver
+from test_propose_vertical import app_with_fake_gitea, tmp_env  # noqa: F401
+from test_rfc_view_vertical import FakeProvider  # noqa: F401
+
+
+def _project(pid: str, visibility: str = "public") -> None:
+    db.conn().execute(
+        "INSERT OR REPLACE INTO projects (id, name, content_repo, visibility, config_json, updated_at) "
+        "VALUES (?, ?, ?, ?, ?, datetime('now'))",
+        (pid, pid.capitalize(), f"{pid}-content", visibility, None),
+    )
+
+
+def _collection(cid: str, project_id: str, *, ctype: str, enabled_models=None) -> None:
+    cfg = None if enabled_models is None else json.dumps({"enabled_models": enabled_models})
+    db.conn().execute(
+        "INSERT OR REPLACE INTO collections "
+        "(id, project_id, type, subfolder, initial_state, visibility, name, config_json, "
+        " created_at, updated_at) "
+        "VALUES (?, ?, ?, ?, 'super-draft', 'public', ?, ?, datetime('now'), datetime('now'))",
+        (cid, project_id, ctype, cid, cid.capitalize(), cfg),
+    )
+
+
+def _entry(slug: str, collection_id: str) -> None:
+    db.conn().execute(
+        "INSERT OR REPLACE INTO cached_rfcs (slug, title, state, collection_id) "
+        "VALUES (?, ?, 'active', ?)",
+        (slug, slug.upper(), collection_id),
+    )
+
+
+def _three_providers(app) -> None:
+    app.state.providers.clear()
+    for k in ("claude", "gemini", "gpt"):
+        app.state.providers[k] = FakeProvider("TITLE: A\nDESCRIPTION: B")
+
+
+def test_two_projects_multicollection_model_universe_isolated(app_with_fake_gitea):
+    app, _ = app_with_fake_gitea
+    with TestClient(app):
+        _three_providers(app)
+        # alpha: a document collection narrowed to claude.
+        _project("alpha")
+        _collection("alpha-docs", "alpha", ctype="document", enabled_models=["claude"])
+        _entry("alpha-intro", "alpha-docs")
+        # beta: two collections — a spec narrowed to gemini, a bdd left open.
+        _project("beta")
+        _collection("beta-specs", "beta", ctype="specification", enabled_models=["gemini"])
+        _collection("beta-features", "beta", ctype="bdd")  # no narrowing → all three
+        _entry("beta-runtime", "beta-specs")
+        _entry("beta-login", "beta-features")
+
+        # Each entry resolves against ITS collection's universe — no bleed.
+        assert models_resolver.resolve_models_for_rfc("alpha-intro", app.state.providers) == ["claude"]
+        assert models_resolver.resolve_models_for_rfc("beta-runtime", app.state.providers) == ["gemini"]
+        assert models_resolver.resolve_models_for_rfc("beta-login", app.state.providers) == [
+            "claude", "gemini", "gpt"
+        ]
+
+
+def test_two_projects_multicollection_type_noun_isolated(app_with_fake_gitea):
+    app, _ = app_with_fake_gitea
+    with TestClient(app):
+        _project("alpha")
+        _collection("alpha-docs", "alpha", ctype="document")
+        _project("beta")
+        _collection("beta-specs", "beta", ctype="specification")
+        _collection("beta-features", "beta", ctype="bdd")
+
+        assert collections.get_collection("alpha-docs")["entry_noun"] == "RFC"
+        assert collections.get_collection("beta-specs")["entry_noun"] == "Spec"
+        assert collections.get_collection("beta-features")["entry_noun"] == "Feature"

backend/tests/test_turnstile_vertical.py

@@ -55,13 +55,19 @@ def _outbound_otc_envelopes(to_address: str | None = None) -> list[dict]:
 
 
 def _patch_siteverify(monkeypatch, *, success: bool, error_codes: list[str] | None = None):
-    """Replace `httpx.post` inside `app.turnstile` with a stub that
+    """Replace `turnstile._siteverify_post` with an async stub that
     returns the requested success shape. The stub does not touch the
     real CloudFlare endpoint and never sees a real secret.
+
+    I4 (security-audit-0026): the siteverify call is now awaited on an
+    `httpx.AsyncClient`, isolated behind the `_siteverify_post` seam.
+    Patching that narrow function (rather than the shared
+    `httpx.AsyncClient`, which gitea/docs also construct) keeps app boot
+    intact.
     """
     captured = {}
 
-    def fake_post(url, *, data=None, timeout=None, **kwargs):
+    async def fake_post(url, data):
         captured["url"] = url
         captured["data"] = data
         body = {"success": bool(success)}
@@ -70,7 +76,7 @@ def _patch_siteverify(monkeypatch, *, success: bool, error_codes: list[str] | No
         return SimpleNamespace(json=lambda: body)
 
     from app import turnstile as turnstile_mod
-    monkeypatch.setattr(turnstile_mod.httpx, "post", fake_post)
+    monkeypatch.setattr(turnstile_mod, "_siteverify_post", fake_post)
     return captured
 
 
@@ -170,14 +176,15 @@ def test_otc_request_admits_when_secret_unset_and_not_required(app_with_fake_git
 
     monkeypatch.delenv("CLOUDFLARE_TURNSTILE_SECRET", raising=False)
     monkeypatch.delenv("TURNSTILE_REQUIRED", raising=False)
-    # The httpx.post inside turnstile must not be called in this path —
-    # patch it to a sentinel that explodes if it ever runs.
+    # The siteverify call inside turnstile must not be made in this path —
+    # patch the seam to a sentinel that explodes if it ever runs
+    # (I4: the seam is now `_siteverify_post`, not module-level httpx.post).
     from app import turnstile as turnstile_mod
 
-    def must_not_be_called(*a, **kw):
+    async def must_not_be_called(*a, **kw):
         raise AssertionError("siteverify should not run when no secret is configured")
 
-    monkeypatch.setattr(turnstile_mod.httpx, "post", must_not_be_called)
+    monkeypatch.setattr(turnstile_mod, "_siteverify_post", must_not_be_called)
 
     app, _fake = app_with_fake_gitea
     with TestClient(app) as client:
@@ -218,3 +225,27 @@ def test_otc_request_refuses_when_required_but_secret_unset(app_with_fake_gitea,
         )
         assert r.status_code == 500, r.text
         assert _outbound_otc_envelopes("alice@example.com") == []
+
+
+# ---------------------------------------------------------------------------
+# I4 (security-audit-0026): verify_token is a coroutine — calling it returns
+# an awaitable, not a VerifyOutcome. Locks the async contract so a revert to
+# the synchronous event-loop-blocking shape fails here, not just in the
+# integration paths.
+# ---------------------------------------------------------------------------
+
+
+def test_verify_token_is_async_and_soft_skips_without_secret(monkeypatch):
+    import asyncio
+
+    from app import turnstile as turnstile_mod
+
+    monkeypatch.delenv("CLOUDFLARE_TURNSTILE_SECRET", raising=False)
+    monkeypatch.delenv("TURNSTILE_REQUIRED", raising=False)
+
+    coro = turnstile_mod.verify_token("any-token")
+    assert asyncio.iscoroutine(coro), "verify_token must be a coroutine (I4)"
+    outcome = asyncio.run(coro)
+    # No secret + not required → the gate stays open without any network call.
+    assert outcome.ok is True
+    assert outcome.reason == "skipped"

backend/tests/test_webhooks_vertical.py

@@ -73,6 +73,7 @@ def test_config_loads_with_empty_secret_when_bypass_is_set(monkeypatch, tmp_path
     monkeypatch.setenv("GITEA_BOT_USER", "rfc-bot")
     monkeypatch.setenv("GITEA_BOT_TOKEN", "bot-token")
     monkeypatch.setenv("GITEA_ORG", "wiggleverse")
+    monkeypatch.setenv("REGISTRY_REPO", "registry")
     monkeypatch.setenv("OAUTH_CLIENT_ID", "cid")
     monkeypatch.setenv("OAUTH_CLIENT_SECRET", "csec")
     monkeypatch.setenv("SECRET_KEY", "test-secret-key")
@@ -92,6 +93,7 @@ def test_config_loads_with_secret_set(monkeypatch, tmp_path):
     monkeypatch.setenv("GITEA_BOT_USER", "rfc-bot")
     monkeypatch.setenv("GITEA_BOT_TOKEN", "bot-token")
     monkeypatch.setenv("GITEA_ORG", "wiggleverse")
+    monkeypatch.setenv("REGISTRY_REPO", "registry")
     monkeypatch.setenv("OAUTH_CLIENT_ID", "cid")
     monkeypatch.setenv("OAUTH_CLIENT_SECRET", "csec")
     monkeypatch.setenv("SECRET_KEY", "test-secret-key")

deploy/DEPLOY-NEW-SESSION-PROMPT.md

@@ -20,15 +20,24 @@ The v1 build is complete (8 slices shipped, 125 passing integration tests). New
 
 The RFC app runs on its own dedicated GCP VM in a separate project from the Gitea VM. The two coexist under `wiggleverse.org` but are otherwise unrelated infrastructure.
 
+> **⚠️ Infrastructure was realigned (GCP name-alignment, ~2026-05).** The
+> GCP project, VM, install path, system user, and systemd unit were all
+> renamed, the static IP changed, and SSH is now **IAP-only** (direct
+> port-22 connections time out). The tables below are the current truth;
+> if you find an older clone of this doc naming `wiggleverse-rfc` /
+> `rfc-app` / `/opt/rfc-app` / `34.132.29.41`, it predates the alignment.
+
 | Property | Value |
 |----------|-------|
-| GCP project | `wiggleverse-rfc` |
-| VM name | `rfc-app` |
+| GCP project | `wiggleverse-ohm` |
+| VM name | `ohm-rfc-app` |
 | VM type | e2-small |
 | Zone | us-central1-a |
 | OS | Debian 12 (bookworm) |
-| Static IP | 34.132.29.41 |
-| Linux user (OS Login) | `benstull` |
+| External IP | `136.116.40.66` |
+| SSH | **IAP-only** — `gcloud compute ssh … --tunnel-through-iap` (port 22 is firewalled off the public internet) |
+| OS Login SSH user | `ben_wiggleverse_org` (auto-derived; you don't type it) |
+| App system user | `ohm-rfc-app` |
 
 For reference, the separate Gitea VM is `wiggleverse` project / `gitea` VM / 34.55.46.221.
 
@@ -36,7 +45,7 @@ For reference, the separate Gitea VM is `wiggleverse` project / `gitea` VM / 34.
 
 | Record | Type | Value | Proxy |
 |--------|------|-------|-------|
-| `ohm.wiggleverse.org` | A | 34.132.29.41 | DNS-only (gray cloud) |
+| `ohm.wiggleverse.org` | A | `136.116.40.66` | DNS-only (gray cloud) |
 | `_dmarc.wiggleverse.org` | TXT | `v=DMARC1; p=none; rua=mailto:ben@wiggleverse.org` | n/a |
 
 > Note: `ohm.wiggleverse.org` uses **Let's Encrypt via certbot** directly on the VM. Keep the A record **DNS only (gray cloud)** — Cloudflare Flexible SSL would conflict with certbot.
@@ -48,24 +57,25 @@ SPF (`v=spf1 include:_spf.google.com ~all`) and DKIM (`google._domainkey`) for `
 | Component | Details |
 |-----------|---------|
 | Backend | Python 3.11, FastAPI, uvicorn (single process) |
-| Database | SQLite in WAL mode at `/opt/rfc-app/backend/data/rfc-app.db` |
+| Database | SQLite in WAL mode at `/opt/ohm-rfc-app/backend/data/rfc-app.db` |
 | Frontend | React 19, Vite 8, Tiptap 3, React Router 7 |
 | Web server | nginx — serves `frontend/dist/` as static SPA, proxies `/api/` and `/auth/` to uvicorn on `127.0.0.1:8000` |
-| Process manager | systemd unit `rfc-app.service`, runs as `rfc-app` system user |
+| Process manager | systemd unit `ohm-rfc-app.service`, runs as `ohm-rfc-app` system user |
 | TLS | Let's Encrypt via certbot |
-| Git backend | Gitea at `git.wiggleverse.org`, bot service account `rfc-bot` |
+| Content Gitea (the bot's writes) | Gitea at `git.wiggleverse.org`, org `wiggleverse`, meta repo `ohm-content` (`wiggleverse/ohm-content`), bot service account `rfc-bot` |
+| Code-deploy source (the VM's git origin) | **`https://git.benstull.org/benstull/rfc-app.git`** — a *different* Gitea from the content one. See the two-remote note under "Deploying a New Version." |
 | Email | Google Workspace SMTP relay (`smtp-relay.gmail.com:587`), AUTH'd as `ben@wiggleverse.org`, From `notifications@wiggleverse.org` |
 
 ### Key Paths on the VM
 
 | Path | Contents |
 |------|---------|
-| `/opt/rfc-app/` | App root (owned by `rfc-app` user) |
-| `/opt/rfc-app/backend/.env` | All secrets and config (mode 0600) |
-| `/opt/rfc-app/backend/data/rfc-app.db` | SQLite database |
-| `/opt/rfc-app/frontend/dist/` | Built React SPA (served by nginx) |
+| `/opt/ohm-rfc-app/` | App root (owned by `ohm-rfc-app` user) |
+| `/opt/ohm-rfc-app/backend/.env` | All secrets and config (mode 0600) |
+| `/opt/ohm-rfc-app/backend/data/rfc-app.db` | SQLite database |
+| `/opt/ohm-rfc-app/frontend/dist/` | Built React SPA (served by nginx) |
 | `/etc/nginx/sites-available/ohm.wiggleverse.org` | nginx vhost config |
-| `/etc/systemd/system/rfc-app.service` | systemd unit |
+| `/etc/systemd/system/ohm-rfc-app.service` | systemd unit |
 
 ---
 
@@ -91,7 +101,7 @@ Created in Gitea as `rfc-bot`. Token scopes: `write:repository`, `write:user`, `
 
 ### Meta repo
 
-`wiggleverse/meta` — seeded by `scripts/seed_meta_repo.py`. Contains `PHILOSOPHY.md`, `README.md`, `CONTRIBUTING.md`, and `rfcs/` directory. Gitea webhook registered to `https://ohm.wiggleverse.org/api/webhooks/gitea`.
+`wiggleverse/ohm-content` (the `META_REPO` value is `ohm-content`) — seeded by `scripts/seed_meta_repo.py`. Contains `PHILOSOPHY.md`, `README.md`, `CONTRIBUTING.md`, and `rfcs/` directory. Gitea webhook registered to `https://ohm.wiggleverse.org/api/webhooks/gitea`.
 
 ### OAuth2 app
 
@@ -167,23 +177,52 @@ HYGIENE_TICK_SECONDS=3600
 
 ## Deploying a New Version
 
-SSH into the VM:
+> **⚠️ Two-remote step — do this FIRST.** The framework's release flow
+> (branches, PRs, version tags) happens on **`git.wiggleverse.org`**
+> (`ben.stull/rfc-app`). But the VM's git origin is a *separate* Gitea,
+> **`git.benstull.org/benstull/rfc-app`**, which does **not** auto-mirror
+> from the release Gitea. So after a release is merged + tagged on
+> `git.wiggleverse.org`, you must push `main` and the new tag to the
+> `benstull` remote before the VM can fetch them:
+> ```bash
+> # from your local rfc-app clone, on main at the merged release tip:
+> git push benstull main vX.Y.Z      # benstull = git@git.benstull.org:benstull/rfc-app.git
+> ```
+> If `git ls-remote benstull vX.Y.Z` comes back empty, the VM cannot see
+> the release yet — push it first. (Wiring the two Gitea instances to
+> mirror would remove this step; until then it's manual.)
+
+SSH into the VM (IAP-only — the `--tunnel-through-iap` flag is required):
 ```bash
-gcloud compute ssh rfc-app --zone=us-central1-a --project=wiggleverse-rfc
+gcloud compute ssh ohm-rfc-app --zone=us-central1-a --project=wiggleverse-ohm --tunnel-through-iap
 ```
 
-Pull the latest code, reinstall deps, restart:
+Fetch + check out the release tag (the VM tracks a **detached** tag, not
+a branch), then restart. Backend deps only need reinstalling when
+`requirements.txt` changed:
 ```bash
-sudo -u rfc-app git -C /opt/rfc-app pull
-sudo -u rfc-app /opt/rfc-app/backend/.venv/bin/pip install \
-    -r /opt/rfc-app/backend/requirements.txt
-sudo systemctl restart rfc-app
+sudo -u ohm-rfc-app git -C /opt/ohm-rfc-app fetch origin --tags
+sudo -u ohm-rfc-app git -C /opt/ohm-rfc-app checkout vX.Y.Z
+# only if backend deps changed:
+sudo -u ohm-rfc-app /opt/ohm-rfc-app/backend/.venv/bin/pip install \
+    -r /opt/ohm-rfc-app/backend/requirements.txt
+sudo systemctl restart ohm-rfc-app
 ```
 
 For frontend changes, build on the VM directly (Node 20+ is already there):
 ```bash
-cd /opt/rfc-app/frontend && sudo -u rfc-app npm ci
-sudo -u rfc-app npm run build
+cd /opt/ohm-rfc-app/frontend && sudo -u ohm-rfc-app npm ci
+sudo -u ohm-rfc-app npm run build
+```
+
+Smoke test (asset hashes change on every rebuild, so a match proves the
+new bundle is live):
+```bash
+# public:
+curl -s -o /dev/null -w '%{http_code} %{remote_ip}\n' https://ohm.wiggleverse.org/
+curl -s https://ohm.wiggleverse.org/ | grep -oE 'assets/index-[A-Za-z0-9_-]+\.(js|css)'
+# backend startup line, on the VM:
+sudo journalctl -u ohm-rfc-app -n 20 --no-pager | grep 'RFC app started'
 ```
 
 `npm ci` installs strictly from the committed `package-lock.json` and
@@ -192,7 +231,7 @@ to rewrite the lockfile in place (notably stripping `libc` fields on
 optional rollup native packages), which then conflicts with `git
 checkout <tag>` on the next deploy.
 
-The output lands in `/opt/rfc-app/frontend/dist/` owned by `rfc-app` — nginx serves it directly, no copy step needed.
+The output lands in `/opt/ohm-rfc-app/frontend/dist/` owned by `ohm-rfc-app` — nginx serves it directly, no copy step needed.
 
 (Building locally and `gcloud compute scp`-ing the dist also works. Plain `rsync -e ssh` from the Mac fails because OS Login uses short-lived SSH certs that only the gcloud wrapper can mint interactively.)
 
@@ -202,6 +241,15 @@ Schema migrations run automatically on restart (append-only, safe to re-run).
 
 ## First-Time Deployment (new server)
 
+> **Note on names:** the command blocks in this section predate the GCP
+> name-alignment and still spell the pre-alignment project/VM/path/user
+> (`wiggleverse-rfc` / `rfc-app` / `/opt/rfc-app` / `rfc-app` /
+> `34.132.29.41`). They're kept as the structural reference. When standing
+> up a box today, substitute the current values from the Host/Paths tables
+> at the top: project `wiggleverse-ohm`, VM `ohm-rfc-app`, install path
+> `/opt/ohm-rfc-app`, system user `ohm-rfc-app`, service `ohm-rfc-app`, IP
+> `136.116.40.66`, and SSH via `--tunnel-through-iap`.
+
 ### 1. Add DNS record
 Add `ohm.wiggleverse.org` → 34.132.29.41 as an A record in Cloudflare, **DNS only (gray cloud)**. Do not proxy — certbot needs to reach the VM directly.
 
@@ -307,7 +355,7 @@ Paste the following into a new Claude session to continue development:
 
 ---
 
-> I'm working on the **Wiggleverse RFC App** — a FastAPI + SQLite + React + Vite application deployed at `ohm.wiggleverse.org` on a GCP e2-small VM (`rfc-app` in the `wiggleverse-rfc` project; separate from the `gitea` VM in `wiggleverse` that runs Gitea at `git.wiggleverse.org`). The app is the primary interface for the Open Human Model (OHM) RFC working group.
+> I'm working on the **Wiggleverse RFC App** — a FastAPI + SQLite + React + Vite application deployed at `ohm.wiggleverse.org` on a GCP e2-small VM (`ohm-rfc-app` in the `wiggleverse-ohm` project; separate from the `gitea` VM in `wiggleverse` that runs Gitea at `git.wiggleverse.org`). The app is the primary interface for the Open Human Model (OHM) RFC working group.
 >
 > **Stack:**
 > - Backend: Python 3.11, FastAPI, uvicorn (single process), SQLite WAL mode
@@ -323,11 +371,12 @@ Paste the following into a new Claude session to continue development:
 > - 10 append-only schema migrations in `backend/migrations/`
 >
 > **Deployment:**
-> - SSH: `gcloud compute ssh rfc-app --zone=us-central1-a --project=wiggleverse-rfc`
-> - Code at `/opt/rfc-app/` on the VM, owned by `rfc-app` system user
-> - `.env` at `/opt/rfc-app/backend/.env` (mode 0600)
-> - Frontend built **on the VM** (Node 20 is installed there) with `npm run build` directly into `/opt/rfc-app/frontend/dist/`
-> - Restart to deploy: `sudo systemctl restart rfc-app`
+> - SSH (IAP-only): `gcloud compute ssh ohm-rfc-app --zone=us-central1-a --project=wiggleverse-ohm --tunnel-through-iap`
+> - Code at `/opt/ohm-rfc-app/` on the VM, owned by `ohm-rfc-app` system user; tracks a detached release **tag**
+> - The VM's git origin is `git.benstull.org/benstull/rfc-app` — a *different* Gitea from the release one (`git.wiggleverse.org`); push `main` + the new tag to the `benstull` remote before deploying
+> - `.env` at `/opt/ohm-rfc-app/backend/.env` (mode 0600)
+> - Frontend built **on the VM** (Node 20 is installed there) with `npm run build` directly into `/opt/ohm-rfc-app/frontend/dist/`
+> - Restart to deploy: `sudo systemctl restart ohm-rfc-app`
 > - Migrations run automatically on startup
 >
 > **Source is at `~/git/rfc-app/`.**

deploy/RUNBOOK.md

@@ -1,9 +1,26 @@
 # Runbook
 
-Single-host deployment of the RFC app at `ohm.wiggleverse.org`, sharing
-infrastructure with `git.wiggleverse.org` (same Gitea instance, same nginx,
-same Let's Encrypt). The shape matches §4.2: one process, one SQLite file,
-no separate worker.
+Single-host deployment of the RFC app at `ohm.wiggleverse.org`. The shape
+matches §4.2: one process, one SQLite file, no separate worker.
+
+> **⚠️ Current deployment names (post GCP name-alignment, ~2026-05).**
+> The command blocks below were written with the original names and use
+> `/opt/rfc-app`, system user `rfc-app`, and service `rfc-app`. The live
+> OHM box uses the realigned names — substitute throughout:
+>
+> | Was | Now |
+> | --- | --- |
+> | GCP project `wiggleverse-rfc` | `wiggleverse-ohm` |
+> | VM `rfc-app` | `ohm-rfc-app` |
+> | install path `/opt/rfc-app` | `/opt/ohm-rfc-app` |
+> | system user `rfc-app` | `ohm-rfc-app` |
+> | service `rfc-app.service` | `ohm-rfc-app.service` |
+> | SSH | IAP-only: `gcloud compute ssh ohm-rfc-app --zone=us-central1-a --project=wiggleverse-ohm --tunnel-through-iap` |
+> | meta repo `wiggleverse/meta` | `wiggleverse/ohm-content` |
+>
+> The VM's git origin is **`git.benstull.org/benstull/rfc-app`** — a
+> *different* Gitea from the release one (`git.wiggleverse.org`). See §2.5.
+> The full current infra table lives in `DEPLOY-NEW-SESSION-PROMPT.md`.
 
 Bring-up order: host prep → Gitea side (bot, OAuth, meta repo) → app side
 (code, venv, build, .env) → web server side (nginx, certbot) → systemd →
@@ -345,16 +362,34 @@ pinned = 1 WHERE rfc_slug = ? AND branch_name = ?`).
 
 ### 2.5 Updating after a push
 
+The live OHM box uses the realigned names (see the callout at the top)
+and deploys by checking out a **release tag** (detached HEAD), not by
+pulling a branch. Its git origin is `git.benstull.org/benstull/rfc-app`,
+which does **not** auto-mirror from the release Gitea
+(`git.wiggleverse.org`) — so first push `main` + the new tag there:
+
 ```sh
-sudo -u rfc-app git -C /opt/rfc-app pull
-sudo -u rfc-app /opt/rfc-app/backend/.venv/bin/pip install \
-    -r /opt/rfc-app/backend/requirements.txt
-# Rebuild the frontend locally and rsync dist/ as in 1.3.2.
-sudo systemctl restart rfc-app
+# from your local rfc-app clone, on main at the merged release tip:
+git push benstull main vX.Y.Z     # benstull = git@git.benstull.org:benstull/rfc-app.git
+```
+
+Then on the VM (SSH is IAP-only):
+
+```sh
+gcloud compute ssh ohm-rfc-app --zone=us-central1-a --project=wiggleverse-ohm --tunnel-through-iap
+sudo -u ohm-rfc-app git -C /opt/ohm-rfc-app fetch origin --tags
+sudo -u ohm-rfc-app git -C /opt/ohm-rfc-app checkout vX.Y.Z
+# only when backend deps changed:
+sudo -u ohm-rfc-app /opt/ohm-rfc-app/backend/.venv/bin/pip install \
+    -r /opt/ohm-rfc-app/backend/requirements.txt
+# frontend changes: build on the VM (Node 20+ is there) — output is served directly by nginx:
+cd /opt/ohm-rfc-app/frontend && sudo -u ohm-rfc-app npm ci && sudo -u ohm-rfc-app npm run build
+sudo systemctl restart ohm-rfc-app
 ```
 
 The §5 schema migrations run on startup and are append-only. A restart
-is the entire deploy.
+is the entire backend deploy; a frontend-only change is live as soon as
+the new `dist/` is built (nginx serves it directly).
 
 ---
 

deploy/nginx/ohm.wiggleverse.org.conf

@@ -8,15 +8,94 @@
 #       /etc/nginx/sites-enabled/
 #   sudo nginx -t && sudo systemctl reload nginx
 #
-# Then add the Let's Encrypt cert:
-#   sudo certbot --nginx -d ohm.wiggleverse.org
-# Certbot will rewrite this file to add the 443 listener and certificate
-# directives; the rest of the config below stays as written.
+# TLS: this vhost terminates with the *.wiggleverse.org wildcard cert installed
+# on the VM (see the ssl_* directives in the 443 block below). This REPLACES the
+# old per-host certbot cert — the live file certbot previously rewrote on the VM
+# is superseded once you install this one. Put the cert files in place first:
+#   sudo install -m 600 -o root -g root privkey.pem   /etc/ssl/private/wiggleverse-wildcard.key
+#   sudo install -m 644           fullchain.pem        /etc/ssl/certs/wiggleverse-wildcard.crt
+# then `sudo nginx -t && sudo systemctl reload nginx`. Once cut over, retire the
+# old cert: `sudo certbot delete --cert-name ohm.wiggleverse.org`.
+#
+# Cloudflare: with an origin wildcard in place, set SSL/TLS mode to Full (strict)
+# and flip ohm to the orange cloud (proxied). If this is a Cloudflare Origin CA
+# cert it ONLY validates behind the proxy — so cut the cert over and proxy in the
+# same change; do not leave ohm grey-cloud with an Origin CA cert.
 
+# HTTP → HTTPS redirect. Cloudflare also redirects at the edge once proxied, but
+# keep the origin honest for direct hits.
 server {
     listen 80;
     listen [::]:80;
     server_name ohm.wiggleverse.org;
+    return 301 https://$host$request_uri;
+}
+
+server {
+    listen 443 ssl http2;
+    listen [::]:443 ssl http2;
+    server_name ohm.wiggleverse.org;
+
+    # TLS — *.wiggleverse.org wildcard installed on the VM (see top comment).
+    # These files must exist before `nginx -t` / reload, or nginx fails to start.
+    ssl_certificate     /etc/ssl/certs/wiggleverse-wildcard.crt;
+    ssl_certificate_key /etc/ssl/private/wiggleverse-wildcard.key;
+    ssl_protocols       TLSv1.2 TLSv1.3;
+    ssl_prefer_server_ciphers off;
+    ssl_session_cache   shared:SSLwiggle:10m;
+    ssl_session_timeout 1d;
+
+    # NOTE: once proxied behind Cloudflare, $remote_addr is a Cloudflare edge IP.
+    # To restore the real client IP (for logging / Turnstile / rate limits), add a
+    # real_ip block (set_real_ip_from <CF ranges>; real_ip_header CF-Connecting-IP;).
+    # Left out here to avoid baking stale CF ranges into the repo — see follow-up.
+
+    # v0.25.0 security hardening (audit 0026 M2/L8)
+    #
+    # NOTE: these response headers live in the HTTPS (443) server block. They use
+    # `add_header ... always` so they also apply to nginx-generated error
+    # responses (4xx/5xx), not just 200s.
+    #
+    # `server_tokens off` (L8) — suppress the nginx version in the
+    # Server header and on error pages so we don't advertise the
+    # build to scanners.
+    server_tokens off;
+
+    add_header Strict-Transport-Security "max-age=31536000; includeSubDomains" always;
+    add_header X-Frame-Options "DENY" always;
+    add_header X-Content-Type-Options "nosniff" always;
+    add_header Referrer-Policy "strict-origin-when-cross-origin" always;
+
+    # Content-Security-Policy (M2). Tuned to what the SPA actually loads:
+    #   - default-src 'self': everything not called out below is same-origin.
+    #   - script-src 'self' + challenges.cloudflare.com: the only external
+    #     <script> tag the app injects is the CloudFlare Turnstile widget
+    #     (frontend/src/components/TurnstileWidget.jsx). Amplitude and
+    #     mermaid are BUNDLED (dynamic `import()` from node_modules, served
+    #     from 'self'), so they need no extra script origin — *.amplitude.com
+    #     is listed defensively in case a future SDK build script-injects.
+    #     script-src DELIBERATELY OMITS 'unsafe-inline' — no inline <script>
+    #     is used, so we keep XSS-via-inline-script blocked.
+    #   - style-src 'unsafe-inline' IS REQUIRED by the current build: the
+    #     JSX uses inline `style={...}` attributes throughout and mermaid
+    #     injects <style> blocks at render time. Removing it would break
+    #     layout; tightening this is a future build-side change (nonce/hash).
+    #   - img-src 'self' data: https: — markdown/RFC bodies may embed remote
+    #     images and data: URIs; svg/mermaid output uses data: too.
+    #   - font-src 'self' data: — bundled fonts plus data: webfonts.
+    #   - connect-src 'self' + *.amplitude.com + challenges.cloudflare.com:
+    #     the app's API/auth/SSE are same-origin (nginx proxy); Amplitude
+    #     Analytics + Session Replay (shipped at sampleRate 1) POST to
+    #     *.amplitude.com; Turnstile verifies via challenges.cloudflare.com.
+    #   - worker-src 'self' blob: — Amplitude Session Replay spins up a
+    #     Web Worker from a blob: URL for capture/compression; without
+    #     blob: here session replay breaks for every consenting user.
+    #   - frame-src challenges.cloudflare.com — the Turnstile challenge
+    #     renders in an iframe from that origin.
+    #   - frame-ancestors 'none' — clickjacking defense, pairs with
+    #     X-Frame-Options DENY for older agents.
+    #   - base-uri 'self'; object-src 'none' — lock down <base>/<object>.
+    add_header Content-Security-Policy "default-src 'self'; script-src 'self' https://challenges.cloudflare.com https://*.amplitude.com; style-src 'self' 'unsafe-inline'; img-src 'self' data: https:; font-src 'self' data:; connect-src 'self' https://*.amplitude.com https://challenges.cloudflare.com; worker-src 'self' blob:; frame-src https://challenges.cloudflare.com; frame-ancestors 'none'; base-uri 'self'; object-src 'none'" always;
 
     # Static SPA assets live in the Vite build output. The systemd unit
     # runs as user `rfc-app`; make sure nginx (usually `www-data`) can
@@ -49,6 +128,28 @@ server {
         proxy_set_header X-Forwarded-Proto $scheme;
     }
 
+    # §22.10: the old corpus-root URLs (/rfc/<slug>, /rfc/<slug>/pr/<n>,
+    # /proposals/<n>) are 308-redirected to the project-scoped /p/<default>/…
+    # routes by the backend, so route them to FastAPI rather than serving the
+    # SPA index.html. Must precede the `location /` SPA fallback.
+    location /rfc/ {
+        proxy_pass http://127.0.0.1:8000;
+        proxy_http_version 1.1;
+        proxy_set_header Host              $host;
+        proxy_set_header X-Real-IP         $remote_addr;
+        proxy_set_header X-Forwarded-For   $proxy_add_x_forwarded_for;
+        proxy_set_header X-Forwarded-Proto $scheme;
+    }
+
+    location /proposals/ {
+        proxy_pass http://127.0.0.1:8000;
+        proxy_http_version 1.1;
+        proxy_set_header Host              $host;
+        proxy_set_header X-Real-IP         $remote_addr;
+        proxy_set_header X-Forwarded-For   $proxy_add_x_forwarded_for;
+        proxy_set_header X-Forwarded-Proto $scheme;
+    }
+
     # SPA fallback — any non-asset path falls back to index.html so
     # React Router can take over.
     location / {