Add frontend components for auto-matching recording partners:
- RecordingTab component with suggestions list and opt-out toggle
- Tab navigation in EventChatPage (Chat, Uczestnicy, Nagrywanie)
- Matching configuration in EventDetailsPage (deadline, run matching)
- matchingAPI functions in api.js
- Return registrationDeadline and matchingRunAt in GET /events/:slug/details
UI allows users to:
- View who will record their heats
- View heats they need to record
- Accept/reject suggestions
- Opt-out from being a recorder
- Set registration deadline (admin)
- Manually trigger matching (admin)
