Use via's embedded NATS server to notify players of state changes
instead of a 100ms polling ticker. Each player subscribes to
"game.<id>" on page load; via auto-cleans subscriptions on disconnect,
eliminating the need for manual player tracking and RegisterSync.
Real-time two-player Connect 4 using Via framework with:
- Game creation and invite links
- SSE-based live updates for both players
- Win detection with animated highlighting
- Session-based nickname persistence
