fix: Restore all files lost during destructive rebase

A previous `git pull --rebase origin main` dropped 177 local commits,
losing 3400+ files across admin-v2, backend, studio-v2, website,
klausur-service, and many other services. The partial restore attempt
(660295e2) only recovered some files.

This commit restores all missing files from pre-rebase ref 98933f5e
while preserving post-rebase additions (night-scheduler, night-mode UI,
NightModeWidget dashboard integration).

Restored features include:
- AI Module Sidebar (FAB), OCR Labeling, OCR Compare
- GPU Dashboard, RAG Pipeline, Magic Help
- Klausur-Korrektur (8 files), Abitur-Archiv (5+ files)
- Companion, Zeugnisse-Crawler, Screen Flow
- Full backend, studio-v2, website, klausur-service
- All compliance SDKs, agent-core, voice-service
- CI/CD configs, documentation, scripts

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

website/app/cancel/page.tsx

@@ -0,0 +1,67 @@
+import Link from 'next/link'
+
+export default function CancelPage() {
+  return (
+    <main className="min-h-screen bg-gradient-to-b from-slate-50 to-white flex items-center justify-center px-4">
+      <div className="max-w-md w-full text-center">
+        {/* Cancel Icon */}
+        <div className="w-20 h-20 bg-slate-100 rounded-full flex items-center justify-center mx-auto">
+          <svg
+            className="w-10 h-10 text-slate-400"
+            fill="none"
+            viewBox="0 0 24 24"
+            stroke="currentColor"
+          >
+            <path
+              strokeLinecap="round"
+              strokeLinejoin="round"
+              strokeWidth={2}
+              d="M6 18L18 6M6 6l12 12"
+            />
+          </svg>
+        </div>
+
+        {/* Message */}
+        <h1 className="mt-6 text-3xl font-bold text-slate-900">
+          Vorgang abgebrochen
+        </h1>
+        <p className="mt-4 text-lg text-slate-600">
+          Sie haben den Checkout-Vorgang abgebrochen.
+          Keine Sorge - es wurden keine Daten gespeichert.
+        </p>
+
+        {/* Options */}
+        <div className="mt-8 space-y-4">
+          <Link
+            href="/#pricing"
+            className="block w-full bg-primary-600 text-white px-8 py-3 rounded-xl font-medium hover:bg-primary-700 transition-all btn-press"
+          >
+            Zurueck zur Planauswahl
+          </Link>
+
+          <Link
+            href="/"
+            className="block w-full bg-slate-100 text-slate-900 px-8 py-3 rounded-xl font-medium hover:bg-slate-200 transition-all"
+          >
+            Zur Startseite
+          </Link>
+        </div>
+
+        {/* FAQ Link */}
+        <div className="mt-8 p-6 bg-slate-50 rounded-xl">
+          <h3 className="font-medium text-slate-900">Haben Sie Fragen?</h3>
+          <p className="mt-2 text-sm text-slate-600">
+            Wenn Sie unsicher sind, welcher Plan der richtige fuer Sie ist,
+            helfen wir Ihnen gerne weiter.
+          </p>
+          <a
+            href="mailto:support@breakpilot.de"
+            className="mt-3 inline-block text-primary-600 hover:underline text-sm font-medium"
+          >
+            support@breakpilot.de
+          </a>
+        </div>
+      </div>
+    </main>
+  )
+}