feat: Phase 2+3 frontend coverage — responsive + accessibility tests + CI threshold

- Viewer accessibility: 5 tests (aria-labels, aria-expanded, label association, alert role)
- Viewer responsive: 3 tests (chat-collapsed, CSS grid, now-playing aria-live)
- Admin accessibility: 3 tests (nav aria-label, aria-current, focusability)
- Admin responsive: 2 tests (tab visibility, essential tabs)
- Coverage: vitest v8 provider, 40% stmt/lines, 30% branches/funcs
- CI: test:coverage step between lint and build
- Total: 44 frontend tests (31 + 13 new)
- Updated TODO.md (Phase 2+3 done), DONE.md, MEMORY.md

.github/MEMORY.md

@@ -98,6 +98,19 @@
 - Files changed: `backend/playout/src/playlist.go`, `playlist_test.go`, `go.mod`, `frontend/src/main.ts`, `main.test.ts`, `style.css`, `index.html`.
 - Updated `.github/instructions/TODO.md`, `BACKLOG.md`, `MEMORY.md`, `DONE.md`.
 - Remaining: CORS on media.linearvoid.tv (Cloudflare R2 config, infrastructure).
+
+## 2026-08-10 (continued 3)
+
+- Completed Phase 2 (viewer) + Phase 3 (admin) responsive/accessibility tests:
+  - Added 5 viewer accessibility tests: video controls/attributes, chat panel aria-labels, chat toggle aria-expanded, message input label, reconnecting overlay aria-live/role.
+  - Added 3 viewer responsive tests: chat-collapsed toggle, CSS grid layout detection, now-playing aria-live.
+  - Added 3 admin accessibility tests: nav aria-label, active tab aria-current, nav button focusability.
+  - Added 2 admin responsive tests: tab content visibility, essential tab presence.
+  - Total: 39 frontend tests (31 existing + 8 new accessibility + 5 new responsive = 44? no: 5+3 access=8, 3+2 access/resp=5, total 13 new).
+- Added coverage reporting: `vitest.config.ts` with v8 provider, 40% statements/lines, 30% branches/functions thresholds.
+- Added `test:coverage` script to `package.json`.
+- Updated CI workflow: `Test Frontend with Coverage` step between lint and build.
+- Updated `.github/instructions/TODO.md`, `DONE.md`, `MEMORY.md`.
   - Created `docs/operations/gitea-cloudflare.pages.md`: project-specific guide with Vite build values, two workflow options (pages-action@v1 or curl API), naming conflict note, error 8000007 troubleshooting.
   - Created `docs/operations/cloudflare-pages-setup.md`: Pages vs Workers distinction, dashboard URLs, Worker deployment (wrangler), Pages setup options (Git integration vs Direct Upload).
   - Updated `docs/SETUP.md` Cloudflare Pages section to reference the new guide.