- Implement per-character voice clip system (match, supermatch, win, lose) that
loads lazily per round and falls back gracefully when clips are missing
- Queue voices to play after arcade cues, with intelligent interruption handling
so only one line plays at a time
- Rename ensureRoundBackgrounds to ensureRoundAssets to handle both images and audio
- Reduce background music volume from 0.8 to 0.4
- Update character sprite sheet and document voice clip structure in sprites.md
- Introduce soundtrack override system allowing games to define custom music
- Add Nintendo-themed soundtrack for Super Kart (2 tracks with metadata)
- Make main menu track configurable via data/music.json instead of hardcoded
- Add MusicPlayer volume parameter for per-soundtrack volume control
- Lazy-load per-game audio assets via assetManifest on game entry
- Add SPACE/X keyboard shortcuts to advance Super Kart menus
- Play kart-spinner SFX when player picks up an item in Super Kart
- Increase speech queue volume to 1.0
- Add Super Kart icons artwork and additional music assets