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/components/auth-view.tsx

@@ -464,6 +464,13 @@ export default function AuthView() {
                     {t('auth.create_student_account')} — {t('auth.student_login_desc')}
                   </p>
                 </div>
+                {/* Jugendschutz notice for students */}
+                <div className="flex items-center justify-center gap-2 px-4 py-3 rounded-lg bg-emerald-50/50 dark:bg-emerald-900/10 border border-emerald-200/30 dark:border-emerald-900/20 mt-2">
+                  <Shield className="h-4 w-4 text-emerald-500" />
+                  <p className="text-xs text-emerald-700 dark:text-emerald-300 font-medium">
+                    {t('dsgvo.jugendschutz_login_notice')}
+                  </p>
+                </div>
               </div>
             )}