Phase 1 (Chess Multiplayer Bulletproof):
- net.js: check content-type before JSON parse, clear error on HTML responses
- modal.js: stack-based resolve — stacked modals no longer hang
- match-session.js: fix null dereference after destroy, remove listener on cleanup
- match-session.js: only fire onConnectionRestored after actual disconnect
- lobby.js: prevent duplicate startGame calls with gameStarted flag
- lobby.js: add pollInFlight guard, clear timeouts on unmount
- lobby.js: derive color from match data when undefined (friend invite fix)
- scene.js: queue navigation during transition instead of dropping it
- chess/game.js: pass timeControl to result scene for correct rematch

Phase 5 (Core UX):
- table.js: hide "My Games" button for non-chess games (no history scenes)
- queue.js: add polling overlap guard
- profile/view.js: show "Unrated" for new players instead of 1200
- i18n: add profile.unrated key (ar/en)
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>