docs: update CLAUDE.md, HELP.md, and TODO for notifications page + push fix

- CLAUDE.md: date → 2026-05-08, add Proactive notifications row to channel table
- HELP.md: update Notifications settings entry, expand Push Notifications section
  with channel config link, add test API endpoints to reference table
- TODO__Agents.md: mark notifications dedicated page and pywebpush fix as done

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

documentation/TODO__Agents.md

@@ -108,6 +108,9 @@ Inara reaches out on her own initiative via NC Talk, Google Chat, email, or brow
 - [x] `scheduler.py` — distill_mid and distill_long already call `notify()` on completion
 - [x] Settings UI — "Browser Push Notification" option added to Notification Channel selector
 - [x] `notification_channel` accepts `"web_push"` in `routers/settings.py`
+- [x] `GET /settings/notifications` — dedicated Notifications page (channel form + test buttons); Settings page now shows a link card
+- [x] `POST /api/push/test` + `POST /api/push/reminders/check` — on-demand test endpoints
+- [x] `push_utils.py` — fixed `pywebpush` 2.x key deserialisation (use `Vapid.from_pem()` instead of passing PEM string)
 
 ### [UI] File attachments in chat
 Upload an image or document inline and have it flow into context. Natural workflow