feat: Unified Inbox in Kommunikation-Navigation hinzugefuegt

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

admin-lehrer/lib/navigation.ts

@@ -39,8 +39,16 @@ export const navigation: NavCategory[] = [
     icon: 'mail',
     color: '#f59e0b', // Amber-500
     colorClass: 'communication',
-    description: 'Video & Chat, Voice Service, Alerts',
+    description: 'Video & Chat, Voice Service, E-Mail, Alerts',
     modules: [
+      {
+        id: 'mail',
+        name: 'Unified Inbox',
+        href: '/communication/mail',
+        description: 'E-Mail-Konten & KI-Analyse',
+        purpose: 'E-Mail-Konten verwalten und KI-Kategorisierung nutzen. IMAP/SMTP Konfiguration, Vorlagen und Audit-Log.',
+        audience: ['Support', 'Admins'],
+      },
       {
         id: 'video-chat',
         name: 'Video & Chat',