Round 19: DSGVO/GDPR compliance, cookie consent, data export, account deletion, Jugendschutz

- Add Cookie Consent component (TTDSG-compliant, essential + analytics cookies)
- Add GDPR Data Export API (DSGVO Art. 20 - data portability)
- Add Account Deletion API (DSGVO Art. 17 - right to erasure, 30-day grace period)
- Add Datenschutz (Privacy) tab in Settings with:
  - Privacy policy (data collected, purpose, retention, third-party sharing)
  - User rights (6 DSGVO rights with descriptions)
  - Data export button (download all personal data as JSON)
  - Account deletion with confirmation dialog and grace period
  - Jugendschutz (youth protection) notices
  - DPA/AVV section for admin (Auftragsverarbeitungsvertrag)
- Add Jugendschutz notice in student login (parental consent for under 16)
- Add 65+ i18n keys for DE and EN (DSGVO, privacy, Jugendschutz, DPA)
- All German law terms accurate (DSGVO, Jugendschutzgesetz, TTDSG, AVV)

src/app/page.tsx

@@ -5,6 +5,7 @@ import { useAppStore } from '@/lib/store';
 import { fetchCurrentUser } from '@/lib/api';
 import AuthView from '@/components/auth-view';
 import AppLayout from '@/components/app-layout';
+import CookieConsent from '@/components/cookie-consent';
 
 export default function Home() {
   const currentUser = useAppStore((s) => s.currentUser);
@@ -48,8 +49,18 @@ export default function Home() {
   }
 
   if (!currentUser) {
-    return <AuthView />;
+    return (
+      <>
+        <AuthView />
+        <CookieConsent />
+      </>
+    );
   }
 
-  return <AppLayout />;
+  return (
+    <>
+      <AppLayout />
+      <CookieConsent />
+    </>
+  );
 }