feat: implement Phase 2 - Matches API with real-time notifications

Backend changes:
- Add matches API routes (POST, GET, PUT, DELETE)
- Create/accept/reject match requests
- Auto-create private chat rooms on match acceptance
- Socket.IO notifications for match events (received, accepted, cancelled)
- Users join personal rooms (user_{id}) for notifications

Frontend changes:
- Add MatchesPage component with inbox UI
- Matches navigation link with notification badge
- Real-time match request count updates
- Accept/reject match functionality
- Filter matches by status (all/pending/accepted)
- Integrate match requests in EventChatPage (UserPlus button)

Features:
- Send match requests to event participants
- Accept incoming match requests
- Real-time notifications via Socket.IO
- Automatic private chat room creation
- Match status tracking (pending/accepted/completed)
- Authorization checks (only participants can match)
- Duplicate match prevention

backend/src/app.js

@@ -79,7 +79,7 @@ app.use('/api/events', require('./routes/events'));
 app.use('/api/wsdc', require('./routes/wsdc'));
 app.use('/api/divisions', require('./routes/divisions'));
 app.use('/api/competition-types', require('./routes/competitionTypes'));
-// app.use('/api/matches', require('./routes/matches'));
+app.use('/api/matches', require('./routes/matches'));
 // app.use('/api/ratings', require('./routes/ratings'));
 
 // 404 handler