Add calendar routes to backend and frontend; update routing and UI components for calendar feature

backend/src/index.js

@@ -82,6 +82,10 @@ app.use('/api/sick', authenticateToken, sickRouter);
 const workdaysRouter = require('./routes/workdays');
 app.use('/api/workdays', authenticateToken, workdaysRouter);
 
+// Calendar routes (geschützt) - MIT ID-Hashing
+const calendarRouter = require('./routes/calendar');
+app.use('/api/calendar', authenticateToken, calendarRouter);
+
 // Error handling middleware
 app.use((err, req, res, next) => {
   console.error(err.stack);