- Canvas coords: scale CSS pixels to logical canvas coordinates properly
  (fixes the offset between where you tap and what gets selected)
- Canvas touchAction:none prevents browser gestures interfering
- Canvas width/height explicitly set in style to match logical size

Home screen redesign:
- Games as 2x2 grid of large colorful tiles (center stage)
- Tap game → bottom sheet menu slides up with:
  - Single Player (bots + local play)
  - Multiplayer (online ranked)
  - Feature chips: Leaderboard, My Matches, Puzzles (chess only)
- No more carousel that gets cut off
- Game-feel: tiles scale down on press, smooth spring animation
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>