✨ feat: add theme toggle functionality and update related files

templates/base.html

@@ -401,7 +401,8 @@
                         @click="darkMode = !darkMode; document.documentElement.classList.toggle('dark', darkMode); localStorage.setItem('darkMode', darkMode ? 'dark' : 'light');"
                         class="p-2 ml-3 rounded-full flex items-center justify-center transition-all duration-300 group focus:outline-none focus:ring-2 focus:ring-indigo-400/50"
                         :class="darkMode ? 'bg-gray-800 hover:bg-gray-700' : 'bg-white/90 hover:bg-white shadow-md'"
-                        aria-label="Themen-Modus wechseln">
+                        aria-label="Themen-Modus wechseln"
+                        data-toggle-theme>
                         
                         <!-- Verbesserte Icon-Container für Light/Dark Mode Toggle -->
                         <div class="relative w-10 h-6 flex items-center justify-center transition-all duration-500">
@@ -813,5 +814,8 @@
         });
       });
     </script>
+
+    <!-- Scripts -->
+    <script src="{{ url_for('static', filename='js/theme-toggle.js') }}"></script>
 </body>
 </html>