Add profile routes to backend and frontend; implement user state handling for holidays and workdays, and update UI components for profile settings

backend/src/index.js

@@ -90,6 +90,10 @@ app.use('/api/calendar', authenticateToken, calendarRouter);
 const holidaysRouter = require('./routes/holidays');
 app.use('/api/holidays', authenticateToken, holidaysRouter);
 
+// Profile routes (geschützt) - MIT ID-Hashing
+const profileRouter = require('./routes/profile');
+app.use('/api/profile', authenticateToken, profileRouter);
+
 // Error handling middleware
 app.use((err, req, res, next) => {
   console.error(err.stack);