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/api/admin/gpu/route.ts

@@ -0,0 +1,82 @@
+/**
+ * GPU Admin API Route - Secure Proxy
+ *
+ * Der vast.ai API-Key wird serverseitig aus der Umgebungsvariable geladen
+ * und niemals an den Client gesendet.
+ */
+
+import { NextRequest, NextResponse } from 'next/server'
+
+// API Key für Backend-Authentifizierung (serverseitig, niemals im Client!)
+// CONTROL_API_KEY ist der Backend-API-Key, VAST_API_KEY ist für vast.ai direkt
+const BACKEND_API_KEY = process.env.CONTROL_API_KEY || process.env.VAST_API_KEY
+
+// Backend URL
+const BACKEND_URL = process.env.BACKEND_URL || 'http://localhost:8000'
+
+export async function GET(request: NextRequest) {
+  if (!BACKEND_API_KEY) {
+    return NextResponse.json(
+      { error: 'CONTROL_API_KEY nicht konfiguriert' },
+      { status: 500 }
+    )
+  }
+
+  try {
+    const response = await fetch(`${BACKEND_URL}/infra/vast/status`, {
+      headers: {
+        'X-API-Key': BACKEND_API_KEY,
+      },
+    })
+
+    const data = await response.json()
+    return NextResponse.json(data, { status: response.status })
+  } catch (error) {
+    console.error('GPU Status fetch error:', error)
+    return NextResponse.json(
+      { error: 'Backend nicht erreichbar', status: 'error' },
+      { status: 503 }
+    )
+  }
+}
+
+export async function POST(request: NextRequest) {
+  if (!BACKEND_API_KEY) {
+    return NextResponse.json(
+      { error: 'CONTROL_API_KEY nicht konfiguriert' },
+      { status: 500 }
+    )
+  }
+
+  try {
+    const body = await request.json()
+    const action = body.action // 'on' or 'off'
+
+    if (!['on', 'off'].includes(action)) {
+      return NextResponse.json(
+        { error: 'Ungültige Aktion' },
+        { status: 400 }
+      )
+    }
+
+    const endpoint = action === 'on' ? '/infra/vast/power/on' : '/infra/vast/power/off'
+
+    const response = await fetch(`${BACKEND_URL}${endpoint}`, {
+      method: 'POST',
+      headers: {
+        'X-API-Key': BACKEND_API_KEY,
+        'Content-Type': 'application/json',
+      },
+      body: JSON.stringify({}),
+    })
+
+    const data = await response.json()
+    return NextResponse.json(data, { status: response.status })
+  } catch (error) {
+    console.error('GPU Power action error:', error)
+    return NextResponse.json(
+      { error: 'Backend nicht erreichbar' },
+      { status: 503 }
+    )
+  }
+}