§22 S2: Catalog + propose scoped to the active collection

Catalog reads the /c/:collectionId/ segment via useCollectionId and fetches the
collection-scoped catalog, building entry/proposal links with the active
collection; the propose modal threads the active collection so a propose from a
named collection targets it.

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

frontend/src/components/Catalog.jsx

@@ -9,7 +9,7 @@
 import { useEffect, useMemo, useState } from 'react'
 import { useParams, Link } from 'react-router-dom'
 import { listRFCs, listProposals } from '../api'
-import { entryPath, proposalPath, useProjectId } from '../lib/entryPaths'
+import { entryPath, proposalPath, useProjectId, useCollectionId } from '../lib/entryPaths'
 
 const STATE_CHIPS = [
   { id: 'super-draft', label: 'Super-draft' },
@@ -32,11 +32,14 @@ export default function Catalog({ viewer, onProposeRFC, version }) {
   const [pendingOpen, setPendingOpen] = useState(true)
   const { slug, prNumber } = useParams()
   const pid = useProjectId()
+  // §22 S2: the catalog is scoped to the active collection (the `/c/:cid/`
+  // route segment, else the project's default collection).
+  const cid = useCollectionId()
 
   useEffect(() => {
-    listRFCs(pid).then(d => setRfcs(d.items)).catch(() => setRfcs([]))
+    listRFCs(pid, cid).then(d => setRfcs(d.items)).catch(() => setRfcs([]))
     listProposals(pid).then(d => setProposals(d.items)).catch(() => setProposals([]))
-  }, [version, pid])
+  }, [version, pid, cid])
 
   const filtered = useMemo(() => {
     const needle = search.trim().toLowerCase()
@@ -105,7 +108,7 @@ export default function Catalog({ viewer, onProposeRFC, version }) {
             return (
               <Link
                 key={r.slug}
-                to={entryPath(pid, r.slug)}
+                to={entryPath(pid, r.slug, cid)}
                 className={`catalog-row ${isActive ? 'active' : ''} ${isSuper ? 'is-super' : ''}`}
               >
                 <div className="row-top">
@@ -133,7 +136,7 @@ export default function Catalog({ viewer, onProposeRFC, version }) {
             {proposals.map(p => (
               <Link
                 key={p.pr_number}
-                to={proposalPath(pid, p.pr_number)}
+                to={proposalPath(pid, p.pr_number, cid)}
                 className={`pending-row ${String(prNumber) === String(p.pr_number) ? 'active' : ''}`}
               >
                 <div>{p.title.replace(/^Propose:\s*/, '')}</div>