Add multi-user auth, background generation, and chat UX improvements
Phase 5: Multi-user authentication with session cookies, bcrypt passwords,
first-user-is-admin pattern, per-user data isolation, backup/restore,
Docker Swarm production stack with secrets and network isolation.
Phase 5.1: Chat UX improvements:
- Background generation architecture (GenerationBuffer + asyncio task)
with SSE fan-out, reconnect support, and periodic DB flushes
- LLM-generated conversation titles (first exchange + every 10th message)
- Stop generation button with cancel_event and partial content preservation
- Relative timestamps in sidebar (5m ago, 3h ago, then dates)
- Empty chat auto-cleanup on navigation away
- Save-as-note uses LLM for title generation, tags notes with "chat"
- Summarize-as-note also tags with "chat"
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
bvandeusen
cbfdf5289e