Slice 2: the §8 active-RFC view in full

Per the §19.1 brief: the three-column shape (§8.1) opens on main
in discuss mode (§8.2), supports the §8.3 discuss-vs-contribute
flip on non-main branches, hosts §8.4's per-branch chat with AI
participation (§18's <change> protocol → §8.14 changes rows), the
§8.8 change-card panel with §8.9 accept/decline/edit-before-accept,
the §8.10 tracked-change markup + DiffView toggle, the §8.11
manual-edit flushes with the stale-change mechanic, the §8.12
range and paragraph sub-threads, the §8.13 flag affordance, and
the §8.14 discuss-mode buffer.

Backend: bot.py grew per-RFC-repo write ops (cut_branch_from_main,
commit_accepted_change with the structured original/proposed/reason
body and Change-Id + Source-Message-Id + On-behalf-of trailers,
commit_manual_flush, ensure_rfc_repo_seed). cache.py grew
refresh_rfc_repo and the webhook dispatches on repository.full_name.
providers.py and chat.py port the §18 carryovers — multi-provider
LLM abstraction and SSE-streaming chat against the §5 threads /
thread_messages / changes schema. api_branches.py mounts the §17
branches/<branch>/* and threads/<thread_id>/* routes with the §6
/ §11 permission checks inline.

Frontend: RFCView.jsx rebuilt as the §8 surface; Editor.jsx,
ChatPanel.jsx, ChangePanel.jsx, PromptBar.jsx, SelectionTooltip.jsx,
DiffView.jsx, ModelPicker.jsx, modelStyles.js lifted from the
prototype and adapted to the canonical schema.

Covered by `backend/tests/test_rfc_view_vertical.py` — eleven new
integration tests against an extended FakeGitea (PUT contents,
POST orgs/{org}/repos, seed_rfc_repo): main-view read,
promote-to-branch, accept (with and without edit-before-accept),
decline, manual flush + system message, flag creation, visibility
flip, anonymous read-but-no-contribute, stale-change refusal, and
the chat-streaming path with a fake provider injected. The 5
Slice 1 tests continue to pass alongside.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

backend/app/webhooks.py

@@ -10,11 +10,12 @@ from __future__ import annotations
 
 import hashlib
 import hmac
+import json
 import logging
 
 from fastapi import APIRouter, Header, HTTPException, Request
 
-from . import cache
+from . import cache, db
 from .config import Config
 from .gitea import Gitea
 
@@ -47,14 +48,25 @@ def make_router(config: Config, gitea: Gitea) -> APIRouter:
         if event not in EVENTS_OF_INTEREST:
             return {"ok": True, "ignored": event}
 
-        # Slice 1 only acts on meta-repo events; per-RFC-repo events
-        # land in their respective slices. The handler is generous in
-        # what it accepts — any meta-repo change is a cue to refresh
-        # the whole meta-repo cache, since the cache is small and the
-        # refresh is idempotent.
+        # Identify the originating repo. For the meta repo we refresh
+        # the entry cache + meta-PR cache; for a per-RFC repo we refresh
+        # just that repo's branches/PRs/main body. The handler stays
+        # generous in what it accepts — refreshes are idempotent and
+        # small enough that overlapping events do not pile up.
         try:
-            await cache.refresh_meta_repo(config, gitea)
-            await cache.refresh_meta_pulls(config, gitea)
+            payload = json.loads(body) if body else {}
+        except Exception:
+            payload = {}
+        repo_full = (payload.get("repository") or {}).get("full_name") or ""
+        meta_full = f"{config.gitea_org}/{config.meta_repo}"
+        try:
+            if repo_full == meta_full or not repo_full:
+                await cache.refresh_meta_repo(config, gitea)
+                await cache.refresh_meta_pulls(config, gitea)
+            else:
+                slug = _slug_for_repo(repo_full)
+                if slug:
+                    await cache.refresh_rfc_repo(config, gitea, slug)
         except Exception:
             log.exception("webhook refresh failed")
             raise HTTPException(status_code=500, detail="Refresh failed")
@@ -69,3 +81,10 @@ def _verify_signature(body: bytes, header: str, secret: str) -> bool:
         return False
     expected = hmac.new(secret.encode("utf-8"), body, hashlib.sha256).hexdigest()
     return hmac.compare_digest(expected, header)
+
+
+def _slug_for_repo(repo_full: str) -> str | None:
+    row = db.conn().execute(
+        "SELECT slug FROM cached_rfcs WHERE repo = ?", (repo_full,)
+    ).fetchone()
+    return row["slug"] if row else None