feat: Add TrainerContextsPage to navigation

- Import TrainerContextsPage in App.jsx
- Add route /trainer-contexts
- Add 'Meine Bereiche' to main navigation (appNav.js)
- Icon: Target (Zielscheibe) für Trainer-Bereiche
- Visible in both desktop sidebar and mobile bottom nav

version: 0.5.0
module: TrainerContextsPage 1.0.0

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

frontend/src/App.jsx

@@ -11,6 +11,7 @@ import ClubsPage from './pages/ClubsPage'
 import SkillsPage from './pages/SkillsPage'
 import TrainingPlanningPage from './pages/TrainingPlanningPage'
 import AdminCatalogsPage from './pages/AdminCatalogsPage'
+import TrainerContextsPage from './pages/TrainerContextsPage'
 import './app.css'
 
 // Bottom Navigation (Mobile)
@@ -189,6 +190,14 @@ function AppRoutes() {
           </ProtectedRoute>
         }
       />
+      <Route
+        path="/trainer-contexts"
+        element={
+          <ProtectedRoute>
+            <TrainerContextsPage />
+          </ProtectedRoute>
+        }
+      />
 
       {/* Catch all - redirect to dashboard or login */}
       <Route path="*" element={<Navigate to="/" replace />} />

frontend/src/config/appNav.js

@@ -4,7 +4,8 @@ import {
   Calendar,
   Building2,
   Settings,
-  Shield
+  Shield,
+  Target
 } from 'lucide-react'
 
 /**
@@ -21,6 +22,7 @@ function baseItems() {
     { to: '/exercises', label: 'Übungen', shortLabel: 'Übungen' },
     { to: '/planning', label: 'Planung' },
     { to: '/clubs', label: 'Vereine' },
+    { to: '/trainer-contexts', label: 'Meine Bereiche', shortLabel: 'Bereiche' },
     { to: '/settings', label: 'Einstellungen', shortLabel: 'Einst.' }
   ]
 }
@@ -32,6 +34,7 @@ export function getMainNavItems(isAdmin) {
     BookOpen,
     Calendar,
     Building2,
+    Target,
     Settings
   ]