fix(§22): catalog scopes to the named collection in the URL (E2E-caught)

useCollectionId read useParams().collectionId, but the Catalog renders at
/p/:projectId/* — outside the c/:collectionId route — so it always fell back
to the default collection. The faceted filter (SLICE-3) and bulk action bar
(SLICE-5) therefore never scoped to a named (fields-bearing) collection in the
deployed app; the Catalog unit test had mocked useCollectionId, hiding it.
Resolve the /c/<id>/ segment from the pathname when the route param isn't in
scope. Caught by the new Playwright metadata suite.

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

frontend/src/lib/useCollectionId.test.jsx

@@ -0,0 +1,42 @@
+// Regression: useCollectionId must resolve the /c/<id>/ segment even when the
+// component renders ABOVE the `c/:collectionId` route (the Catalog's position
+// at `/p/:projectId/*`), where useParams() does not expose collectionId. A bug
+// here makes the faceted/bulk catalog silently scope to the default collection.
+import { describe, it, expect } from 'vitest'
+import { renderHook } from '@testing-library/react'
+import { MemoryRouter, Routes, Route } from 'react-router-dom'
+import { useCollectionId } from './entryPaths.js'
+
+function wrapperFor(initialPath, routePath) {
+  return ({ children }) => (
+    <MemoryRouter initialEntries={[initialPath]}>
+      <Routes>
+        <Route path={routePath} element={children} />
+      </Routes>
+    </MemoryRouter>
+  )
+}
+
+describe('useCollectionId', () => {
+  it('reads the /c/<id>/ segment from the path at the Catalog level (no param in scope)', () => {
+    // The Catalog matches `/p/:projectId/*` — collectionId is NOT a param here.
+    const { result } = renderHook(() => useCollectionId(), {
+      wrapper: wrapperFor('/p/ohm/c/bdd/e/checkout', '/p/:projectId/*'),
+    })
+    expect(result.current).toBe('bdd')
+  })
+
+  it('honours the route param when in scope', () => {
+    const { result } = renderHook(() => useCollectionId(), {
+      wrapper: wrapperFor('/p/ohm/c/features/e/login', '/p/:projectId/c/:collectionId/*'),
+    })
+    expect(result.current).toBe('features')
+  })
+
+  it('falls back to the default collection when there is no /c/ segment', () => {
+    const { result } = renderHook(() => useCollectionId(), {
+      wrapper: wrapperFor('/p/ohm', '/p/:projectId/*'),
+    })
+    expect(result.current).toBe('default')
+  })
+})