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>

klausur-service/frontend/src/components/Layout.tsx

@@ -0,0 +1,38 @@
+import { ReactNode } from 'react'
+
+interface LayoutProps {
+  children: ReactNode
+}
+
+export default function Layout({ children }: LayoutProps) {
+  const handleBackToStudio = () => {
+    // Navigate back to Studio
+    if (window.parent !== window) {
+      window.parent.postMessage({ type: 'CLOSE_KLAUSUR_SERVICE' }, '*')
+    } else {
+      window.location.href = '/studio'
+    }
+  }
+
+  return (
+    <div className="app-layout">
+      <div className="main-content">
+        <header className="topbar">
+          <div className="brand">
+            <div className="brand-logo">BP</div>
+            <div className="brand-text">
+              <span className="brand-text-main">BreakPilot</span>
+              <span className="brand-text-sub">Klausur-Korrektur</span>
+            </div>
+          </div>
+          <div className="topbar-actions">
+            <button className="btn btn-ghost" onClick={handleBackToStudio}>
+              Zurueck zum Studio
+            </button>
+          </div>
+        </header>
+        {children}
+      </div>
+    </div>
+  )
+}