Make web app mobile-friendly: responsive CSS, touch drawing, safe areas, keyboard handling

Fix AI toggle no-op, add (beta) label

Restore AI Player toggle and QuickDraw bar UI

Restore QuickDraw AI model files and TF.js CDN script

Remove TensorFlow.js CDN script (no longer needed)

Remove AI player and QuickDraw recognition

Replace admin system with TOTP mod system, defer QuickDraw model loading, fix teams-mode sync, add AI-only-when-alone guard

Initial commit: Skrawl multiplayer drawing game with QuickDraw AI recognition