feat(cmp): GDPR-compliant DSE + consent re-open button

- Rewrite Datenschutzerklaerung: cookie section with bp_consent table,
  legal basis (Art. 6(1)(a) + §25 TDDDG), DPO, Hetzner hosting, Google
  Fonts DPF, retention periods, all data subject rights (Art. 15-21),
  supervisory authority (LfD Niedersachsen)
- Add "Cookie-Einstellungen" re-open button in footer (Art. 7(3) DSGVO)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

marketing-website/components/layout/Footer.tsx

@@ -1,8 +1,14 @@
 'use client'
 
+import { Cookie } from 'lucide-react'
 import { t } from '@/lib/content'
 import { useApp } from '@/lib/context'
 
+function reopenConsentBanner() {
+  localStorage.removeItem('bp_consent')
+  window.location.reload()
+}
+
 export default function Footer() {
   const { lang } = useApp()
   const i = t(lang)
@@ -59,9 +65,18 @@ export default function Footer() {
           <p className="text-xs text-white/20">
             &copy; {year} {i.footer.copyright}. Alle Rechte vorbehalten.
           </p>
-          <p className="text-xs text-white/20 font-mono">
-            {i.footer.madeIn}
-          </p>
+          <div className="flex items-center gap-4">
+            <button
+              onClick={reopenConsentBanner}
+              className="text-xs text-white/20 hover:text-white/50 transition-colors flex items-center gap-1.5"
+            >
+              <Cookie className="w-3 h-3" />
+              Cookie-Einstellungen
+            </button>
+            <p className="text-xs text-white/20 font-mono">
+              {i.footer.madeIn}
+            </p>
+          </div>
         </div>
       </div>
     </footer>