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>

admin-v2/app/api/education/abitur-docs/route.ts

@@ -0,0 +1,139 @@
+import { NextRequest, NextResponse } from 'next/server'
+
+/**
+ * Proxy to backend /api/abitur-docs
+ * Lists and manages Abitur documents (NiBiS, etc.)
+ */
+
+const BACKEND_URL = process.env.BACKEND_URL || 'http://localhost:8000'
+
+export async function GET(request: NextRequest) {
+  try {
+    const { searchParams } = new URL(request.url)
+
+    // Forward all query params to backend
+    const queryString = searchParams.toString()
+    const url = `${BACKEND_URL}/api/abitur-docs/${queryString ? `?${queryString}` : ''}`
+
+    const response = await fetch(url, {
+      method: 'GET',
+      headers: {
+        'Content-Type': 'application/json',
+      },
+    })
+
+    if (!response.ok) {
+      // Return mock data for development if backend is not available
+      if (response.status === 404 || response.status === 502) {
+        return NextResponse.json(getMockDocuments(searchParams))
+      }
+      throw new Error(`Backend responded with ${response.status}`)
+    }
+
+    const data = await response.json()
+
+    // If backend returns empty array, use mock data for demo purposes
+    // (Backend uses in-memory storage which is lost on restart)
+    if (Array.isArray(data) && data.length === 0) {
+      console.log('Backend returned empty array, using mock data')
+      return NextResponse.json(getMockDocuments(searchParams))
+    }
+
+    // Handle paginated response with empty documents
+    if (data.documents && Array.isArray(data.documents) && data.documents.length === 0 && data.total === 0) {
+      console.log('Backend returned empty documents, using mock data')
+      return NextResponse.json(getMockDocuments(searchParams))
+    }
+
+    return NextResponse.json(data)
+  } catch (error) {
+    console.error('Abitur docs list error:', error)
+    // Return mock data for development
+    return NextResponse.json(getMockDocuments(new URL(request.url).searchParams))
+  }
+}
+
+function getMockDocuments(searchParams: URLSearchParams) {
+  const page = parseInt(searchParams.get('page') || '1')
+  const limit = parseInt(searchParams.get('limit') || '20')
+  const fach = searchParams.get('fach')
+  const jahr = searchParams.get('jahr')
+  const bundesland = searchParams.get('bundesland')
+
+  // Generate mock documents
+  const allDocs = generateMockDocs()
+
+  // Apply filters
+  let filtered = allDocs
+  if (fach) {
+    filtered = filtered.filter(d => d.fach === fach)
+  }
+  if (jahr) {
+    filtered = filtered.filter(d => d.jahr === parseInt(jahr))
+  }
+  if (bundesland) {
+    filtered = filtered.filter(d => d.bundesland === bundesland)
+  }
+
+  // Paginate
+  const start = (page - 1) * limit
+  const docs = filtered.slice(start, start + limit)
+
+  return {
+    documents: docs,
+    total: filtered.length,
+    page,
+    limit,
+    total_pages: Math.ceil(filtered.length / limit),
+  }
+}
+
+function generateMockDocs() {
+  const faecher = ['deutsch', 'mathematik', 'englisch', 'biologie', 'physik', 'chemie', 'geschichte']
+  const jahre = [2024, 2025]
+  const niveaus = ['eA', 'gA']
+  const typen = ['aufgabe', 'erwartungshorizont']
+  const nummern = ['I', 'II', 'III']
+
+  const docs = []
+  let id = 1
+
+  for (const jahr of jahre) {
+    for (const fach of faecher) {
+      for (const niveau of niveaus) {
+        for (const nummer of nummern) {
+          for (const typ of typen) {
+            const suffix = typ === 'erwartungshorizont' ? '_EWH' : ''
+            const dateiname = `${jahr}_${capitalize(fach)}_${niveau}_${nummer}${suffix}.pdf`
+
+            docs.push({
+              id: `doc-${id++}`,
+              dateiname,
+              original_dateiname: dateiname,
+              bundesland: 'niedersachsen',
+              fach,
+              jahr,
+              niveau,
+              typ,
+              aufgaben_nummer: nummer,
+              status: 'indexed',
+              confidence: 0.95,
+              file_path: `/tmp/abitur-docs/${dateiname}`,
+              file_size: Math.floor(Math.random() * 500000) + 100000,
+              indexed: true,
+              vector_ids: [`vec-${id}-1`, `vec-${id}-2`],
+              created_at: new Date(Date.now() - Math.random() * 30 * 24 * 60 * 60 * 1000).toISOString(),
+              updated_at: new Date().toISOString(),
+            })
+          }
+        }
+      }
+    }
+  }
+
+  return docs
+}
+
+function capitalize(str: string): string {
+  return str.charAt(0).toUpperCase() + str.slice(1)
+}