- Extend SnapDetector to include distance and neighbor IDs in glow segment data
- Add CSS animations for spinning border shimmer effects on puzzle selection cards
- Implement dynamic hover/selection states with scale transform and glow effects on cards
- Add puzzle view mode guard to prevent interaction during completed state display
- Refactor piece glow system: replace static multi-pass lines with dynamic intensity-based fading, add per-piece preFX glow, and include proper cleanup of timers/glow FX
- Add clean texture variants (`piece_clean_N`) for merged pieces to remove outlines after grouping
- Improve piece renderer progress tracking to distinguish main vs. clean textures
- Support 140-piece puzzles (14×10 grid) across generator, menu, and selection scenes
- Auto-open join dialog when `?room=` URL parameter present in main menu
- Add shareable room link with copy-to-clipboard button in puzzle scene UI
- Introduce `_updatePieceEffects()` to manage visual states: clean textures for merged groups, drop shadows for singletons/groups
- Enhance music playback with fallback completion detection and robust event handling
Brian Fertig