feat: enhance calendar functionality with dayGrid and timeGrid plugins

Web/templates/terminplan.html

@@ -172,6 +172,8 @@
 
 <link href="https://cdn.jsdelivr.net/npm/fullcalendar@5.10.1/main.min.css" rel="stylesheet">
 <script src="https://cdn.jsdelivr.net/npm/fullcalendar@5.10.1/main.min.js"></script>
+<script src="https://cdn.jsdelivr.net/npm/fullcalendar@5.10.1/daygrid/main.min.js"></script>
+<script src="https://cdn.jsdelivr.net/npm/fullcalendar@5.10.1/timegrid/main.min.js"></script>
 <script src="https://cdn.jsdelivr.net/npm/fullcalendar@5.10.1/locales/de.js"></script>
 
 <script>
@@ -252,6 +254,7 @@ document.addEventListener('DOMContentLoaded', function() {
 
     // Initialize calendar
     calendar = new FullCalendar.Calendar(calendarEl, {
+        plugins: [FullCalendar.dayGridPlugin, FullCalendar.timeGridPlugin],
         initialView: 'timeGridDay',
         locale: 'de',
         headerToolbar: false, // We're using our custom header
@@ -428,7 +431,10 @@ document.addEventListener('DOMContentLoaded', function() {
         eventClick: function(info) {
             showEventDetails(info.event);
         },
-        datesSet: function(dateInfo) {
+        datesSet: function() {
+            updateCurrentDayDisplay();
+        }
+    });
 
     function setCalendarView(viewName) {
         activeCalendarView = viewName;
@@ -442,15 +448,12 @@ document.addEventListener('DOMContentLoaded', function() {
         button.addEventListener('click', function() {
             setCalendarView(this.dataset.calendarView);
         });
-    });
-            updateCurrentDayDisplay();
-        }
-    setCalendarView(activeCalendarView);
     });
 
     // Render calendar
     try {
         calendar.render();
+        setCalendarView(activeCalendarView);
         
         setTimeout(() => {
             calendar.updateSize();