Socket.IO Real-time Application

Create Socket.IO application for:

Application Type: {{APP_TYPE}} (chat/game/collaboration)
Server Framework: {{FRAMEWORK}}
Features: {{FEATURES}}

Generate complete Socket.IO structure:

1. **Server Setup:**
   - Socket.IO initialization
   - CORS configuration
   - Authentication middleware
   - Connection handling
   - Disconnection cleanup

2. **Event Handlers:**
   - Event registration
   - Event validation
   - Broadcast patterns
   - Acknowledgments
   - Error handling

3. **Rooms and Namespaces:**
   - Namespace organization
   - Room management
   - Join/leave logic
   - Room broadcasting

4. **Authentication:**
   - Socket middleware
   - JWT verification
   - Session integration
   - User identification

5. **Client Setup:**
   - Connection management
   - Reconnection handling
   - Event listeners
   - Emit patterns

6. **React Integration:**
   - useSocket hook
   - Context provider
   - Event subscriptions
   - Cleanup handling

7. **State Synchronization:**
   - Initial state sync
   - Delta updates
   - Conflict resolution
   - Optimistic updates

8. **Scaling:**
   - Redis adapter
   - Sticky sessions
   - Horizontal scaling
   - Load balancing

9. **Testing:**
   - Socket.IO client mock
   - Integration tests
   - Event testing

Include presence system example.