feat(Tournament): add official tournament participation feature

- Introduced functionality to load and display official tournament participation events in the CalendarView.
- Updated the API client to fetch official tournament data, enhancing the event management capabilities.
- Added new UI elements to represent official tournaments, including visual indicators and event details.
- Enhanced the ClubManager to support fetching and managing official tournament data.
- Updated the mobile app's TODO list to reflect progress on tournament-related features.

backend/services/tournamentService.js

@@ -1008,7 +1008,7 @@ class TournamentService {
         return JSON.parse(JSON.stringify(tournaments));
     }
 
-Ve    // 2. Neues Turnier anlegen
+    // 2. Neues Turnier anlegen
     async addTournament(userToken, clubId, tournamentName, date, winningSets, allowsExternal, isDoublesTournament = false) {
         await checkAccess(userToken, clubId);
         const t = await Tournament.create({