Three critical multiplayer sync issues fixed:

1. Resign now notifies server (action:'resign') BEFORE ending locally.
   Opponent's polling detects status:'completed' + result and shows win.

2. Reconnect recovery completely rewritten:
   - Determines player color from match data (white_player_id vs userId)
   - Flips board correctly for black
   - Sets lastKnownMoveCount from server to prevent duplicate move processing
   - Detects if game already ended while disconnected (opponent resigned)
   - Restores canSelect with correct color check

3. sendLiveMove now includes clock times (white_time_remaining_ms,
   black_time_remaining_ms) so opponent sees accurate clocks.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>