Refactor(board): major performance improvements and interaction bug fixes

[Klimbar]

This PR introduces a major overhaul to the chessboard rendering logic, significantly improving performance, fixing interaction bugs, and adding new shortcut features for a smoother gameplay and analysis experience.

• Custom Piece Rendering: Replaced the default piece renderer with a highly optimized CustomPiece component. This prevents unnecessary re-renders across the board during interactions and uses hardware acceleration (translateZ) for z-index management.

• Preloaded Assets: Added <link rel="preload"> to _document.tsx for the default maestro king and pawn SVGs, drastically cutting down the perceived initial load time.

• Zero-Latency Drops: Dynamically disables piece transition animations when a piece is dropped to ensure instantaneous visual snapping.

• Jotai State Granularity: Refactored currentPositionAtom usage to derive primitive values, preventing the board from re-rendering every time the complex engine evaluation object updates.

• Drag Cancellation Fix: Fixed a bug where a right-click during a piece drag would incorrectly drop the piece if it's a movable square. Implemented a custom ghost-piece system animateReturnFlight() to smoothly fly the piece back to its origin square upon cancellation.

• Annotation Modifiers:

  • `Ctrl + Right Click: Draws red arrows with yellow squares.
  • Alt + Right Click: Draws blue arrows with blue squares.
  • Default Right Click remains yellow arrows with red squares.

• Spacebar Best Move Shortcut: Implemented a global keyboard listener (ignoring input fields) that allows users to instantly execute the engine's current top recommended move by pressing the spacebar.

• Check Visuals and Audio: Added a red drop-shadow filter to the King when in check. Also integrated a new check.mp3 sound effect to trigger on checking moves.

• Stale State Prevention: Added FEN tracking to the CurrentPosition type. This ensures that old engine lines and previous opening names don't briefly flash on the UI during rapid, multi-move sequences.

• CSS Improvements: Added board.css to remove mobile swipe defaults (touch-action: none), improve piece dragging cursors, and fix z-index clipping issues with the promotion dialog.

• Added bench.js at the root directory for profiling chess.js history and PGN loading performance.

• Added a circle indicator to the capturable pieces after clicking on a piece.

[GuillaumeSD]

Thanks for your PR @Klimbar , I have read it quickly and it seems of high quality, good job 👍
Due to my lack of free time currently and the amount of changes this PR brings, bear in mind that I won't be able to review and handle it quickly.