feat(chess-ui): gamify starting/end states and in-game checks

[cto-new]

Summary

Enhance the chess UI with gamified feedback for start and end of games, check/mate states, and richer status visuals. Improve user experience with animated overlays, move history, and status indicators.

Details

• Introduce GameStatus and GameStartOverlay components to display dynamic game state and end-of-game feedback.
• Integrate new status indicators into the game flow, including check, checkmate, stalemate, and draw visuals with toasts and confetti on end.
• Extend ChessBoard to highlight check squares and provide visual cues for valid moves.
• Track and expose in-game state (isInCheck, isCheckmate, isStalemate, isDraw) to drive UI overlays.
• Add animated overlays and a richer side panel showing turn, move history, and opponent status.
• Wire game page to pass new props and manage new UI state.

Warning: Task VM test is not passing, cto.new will perform much better if you fix the setup