docs: update documentation with recent features

- Update README.md with tier system and recent features
- Add 3-tier account system (BASIC/SUPPORTER/COMFORT) to docs
- Document fairness algorithm and dual buffer system
- Add clickable usernames and country flags features
- Update test count to 285/286 passing (99.7%)
- Update database schema documentation with tier fields
- Update all last modified dates to 2025-11-29

docs/TODO.md

@@ -7,14 +7,17 @@
 ## Current Status
 
 **Phase:** MVP Complete - Ready for Production Deployment
-**Tests:** 286/286 passing (73% coverage)
+**Tests:** 285/286 passing - 99.7% (73% coverage)
 **Status:** Awaiting infrastructure setup
 
-### Recently Completed (2025-11-23)
-- Recording Matching System (auto-assign recorders for heats)
-- Competitor Number (Bib) Support
-- Frontend Refactoring (component extraction, status constants)
-- Dashboard with real-time updates (online count, unread messages)
+### Recently Completed (2025-11-29)
+- 3-Tier Account System (BASIC/SUPPORTER/COMFORT) with fairness algorithm
+- Dual Buffer System (prep before + rest after dancing)
+- Clickable Usernames with @ prefix in profiles
+- Country Flags in Event Chat
+- Mobile-first Design Improvements (page titles on mobile)
+- Recording Matching System Improvements (collision detection, schedule config)
+- Test Bot for Automated Testing
 
 **Full history:** See `docs/archive/COMPLETED.md`
 
@@ -114,5 +117,5 @@ http://localhost:8080
 
 ---
 
-**Last Updated:** 2025-11-23
+**Last Updated:** 2025-11-29
 **Full Details:** See `docs/archive/COMPLETED.md` for implementation details