§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>

frontend/src/components/Catalog.jsx

@@ -31,6 +31,9 @@ export default function Catalog({ viewer, onProposeRFC, version }) {
   // collection's caps load; we fall back to "any authenticated viewer" so the
   // common case doesn't flicker, then refine.
   const [canContribute, setCanContribute] = useState(null)
+  // §22.4a: the type-driven entry noun ("RFC" | "Spec" | "Feature") for this
+  // collection, read from the API. Defaults to the generic "RFC" until loaded.
+  const [entryNoun, setEntryNoun] = useState('RFC')
   const [search, setSearch] = useState('')
   const [sort, setSort] = useState('recent')
   const [activeChips, setActiveChips] = useState(new Set())
@@ -46,7 +49,10 @@ export default function Catalog({ viewer, onProposeRFC, version }) {
     listProposals(pid).then(d => setProposals(d.items)).catch(() => setProposals([]))
     setCanContribute(null)
     getCollection(pid, cid)
-      .then(c => setCanContribute(!!c?.viewer?.can_contribute))
+      .then(c => {
+        setCanContribute(!!c?.viewer?.can_contribute)
+        setEntryNoun(c?.entry_noun || 'RFC')
+      })
       .catch(() => setCanContribute(false))
   }, [version, pid, cid])
 
@@ -177,7 +183,7 @@ export default function Catalog({ viewer, onProposeRFC, version }) {
           // contribute to *this* collection (the scope-role gate); a granted
           // viewer with no contribute right in this collection sees nothing.
           mayPropose && (
-            <button className="btn-propose" onClick={onProposeRFC}>+ Propose New RFC</button>
+            <button className="btn-propose" onClick={onProposeRFC}>+ Propose New {entryNoun}</button>
           )
         ) : (
           <a className="btn-propose" href="/auth/login" title="Private beta — only invited emails can propose">