optimized admin protection

frontend/src/components/Sidebar.jsx

@@ -1,11 +1,13 @@
 import { Link, useLocation, useNavigate } from 'react-router-dom'
 import { useAuth } from '../contexts/AuthContext'
+import { usePermissions } from '../contexts/PermissionsContext'
 import { useState, useEffect } from 'react'
 
 const Sidebar = ({ isOpen, setIsOpen }) => {
   const location = useLocation()
   const navigate = useNavigate()
   const { user, logout } = useAuth()
+  const { isAdmin } = usePermissions()
   const [expandedMenus, setExpandedMenus] = useState({})
 
   const menuItems = [
@@ -128,7 +130,8 @@ const Sidebar = ({ isOpen, setIsOpen }) => {
               </li>
             ))}
             
-            {/* Settings Menu mit Unterpunkten */}
+            {/* Settings Menu mit Unterpunkten - nur für Admins */}
+            {isAdmin && (
             <li>
               <button
                 onClick={() => isOpen && toggleMenu(settingsMenu.path)}
@@ -184,6 +187,7 @@ const Sidebar = ({ isOpen, setIsOpen }) => {
                 </ul>
               )}
             </li>
+            )}
           </ul>
           {/* Profil-Eintrag und Logout am unteren Ende */}
           <div className="mt-auto pt-2 border-t border-slate-700/50 space-y-2">