§22 S6: type-driven entry noun (§22.4a) — backend source of truth + chrome

The displayed noun for an entry is a framework concept keyed on the collection's
immutable type — document→"RFC", specification→"Spec", bdd→"Feature" — not
deployment content. The chrome reads it from the API instead of hardcoding "RFC".

- collections.ENTRY_NOUN + entry_noun(type) (unknown type → generic "RFC").
- Surfaced as entry_noun on get_collection, list_collections items, the
  /api/deployment directory items, and GET /api/projects/:id.
- Frontend: Catalog reads entry_noun for the "+ Propose New <noun>" control;
  ProposeModal fetches the active collection's noun for its title + field copy.
- test_s6_entry_noun_vertical.py: map + API surfacing (collection + directory).

Scope note: this is §22.4a item (2) — terminology. The deeper type-module work
(item 1 per-type frontmatter schemas; item 3 specification release-planning +
bdd scenario/coverage surfaces) is flagged OPEN in the design doc and is handed
off to a follow-up spec+slice.

Backend 528 passed; frontend 30 passed + build green. Part of v0.45.0.

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

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"