feat: arena HUD, eval bar, game-over screen, CRT theme

- VS-style HUD: face, captured pieces, material chip, life-bar clocks
- vertical eval bar fed by the engine after each move (queued, never
  interleaved with search)
- last-move arrow for engine moves, drawn on an SVG layer
- checkmate ceremony: board shake, fallen king, end screen with
  rematch / new opponent / menu
- opponent dossier with ASCII stat bars on the new-game screen
- CRT theme (phosphor green, scanlines) and pixel-weight buttons
- new sounds: start, castle, promotion, low-time tick
- drop tsc-emitted .js from src (noEmit) so dev always serves the .ts
- destroy board window listeners when a game ends

feat: fix colors

feat: very small fix on mime and wasm

first commit