feat(Calendar): integrate CalendarEvent model and enhance calendar functionality

- Added CalendarEvent model to the backend, establishing relationships with the Club model for better event management.
- Updated server.js to include calendarEventRoutes, enabling API access for calendar events.
- Enhanced CalendarView.vue to support custom event creation and management, improving user interaction with the calendar.
- Refactored various components to streamline event handling and improve overall user experience in the calendar interface.
- Updated TODO and DEVELOPMENT documentation to reflect new calendar features and architectural decisions.

backend/routes/calendarEventRoutes.js

@@ -0,0 +1,16 @@
+import express from 'express';
+import { authenticate } from '../middleware/authMiddleware.js';
+import {
+  createClubCalendarEvent,
+  deleteClubCalendarEvent,
+  listClubCalendarEvents,
+} from '../controllers/calendarEventController.js';
+
+const router = express.Router();
+router.use(authenticate);
+
+router.get('/:clubId', listClubCalendarEvents);
+router.post('/:clubId', createClubCalendarEvent);
+router.delete('/:clubId/:eventId', deleteClubCalendarEvent);
+
+export default router;