[split-required] Split 500-1000 LOC files across all services

backend-lehrer (5 files):
- alerts_agent/db/repository.py (992 → 5), abitur_docs_api.py (956 → 3)
- teacher_dashboard_api.py (951 → 3), services/pdf_service.py (916 → 3)
- mail/mail_db.py (987 → 6)

klausur-service (5 files):
- legal_templates_ingestion.py (942 → 3), ocr_pipeline_postprocess.py (929 → 4)
- ocr_pipeline_words.py (876 → 3), ocr_pipeline_ocr_merge.py (616 → 2)
- KorrekturPage.tsx (956 → 6)

website (5 pages):
- mail (985 → 9), edu-search (958 → 8), mac-mini (950 → 7)
- ocr-labeling (946 → 7), audit-workspace (871 → 4)

studio-v2 (5 files + 1 deleted):
- page.tsx (946 → 5), MessagesContext.tsx (925 → 4)
- korrektur (914 → 6), worksheet-cleanup (899 → 6)
- useVocabWorksheet.ts (888 → 3)
- Deleted dead page-original.tsx (934 LOC)

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

website/app/admin/ocr-labeling/_components/ExportTab.tsx

@@ -0,0 +1,113 @@
+'use client'
+
+import { useState } from 'react'
+import type { OCRSession, OCRStats } from '../types'
+
+const API_BASE = process.env.NEXT_PUBLIC_KLAUSUR_SERVICE_URL || 'http://localhost:8086'
+
+export default function ExportTab({
+  sessions,
+  selectedSession,
+  setSelectedSession,
+  stats,
+  onError,
+}: {
+  sessions: OCRSession[]
+  selectedSession: string | null
+  setSelectedSession: (id: string | null) => void
+  stats: OCRStats | null
+  onError: (msg: string) => void
+}) {
+  const [exportFormat, setExportFormat] = useState<'generic' | 'trocr' | 'llama_vision'>('generic')
+  const [exporting, setExporting] = useState(false)
+  const [exportResult, setExportResult] = useState<any>(null)
+
+  const handleExport = async () => {
+    setExporting(true)
+    try {
+      const res = await fetch(`${API_BASE}/api/v1/ocr-label/export`, {
+        method: 'POST',
+        headers: { 'Content-Type': 'application/json' },
+        body: JSON.stringify({
+          export_format: exportFormat,
+          session_id: selectedSession,
+        }),
+      })
+
+      if (res.ok) {
+        const data = await res.json()
+        setExportResult(data)
+      } else {
+        onError('Export fehlgeschlagen')
+      }
+    } catch (err) {
+      onError('Netzwerkfehler')
+    } finally {
+      setExporting(false)
+    }
+  }
+
+  return (
+    <div className="space-y-6">
+      <div className="bg-white rounded-lg shadow p-6">
+        <h3 className="text-lg font-semibold mb-4">Training-Daten exportieren</h3>
+        <div className="space-y-4">
+          <div>
+            <label className="block text-sm font-medium text-slate-700 mb-1">Export-Format</label>
+            <select
+              value={exportFormat}
+              onChange={(e) => setExportFormat(e.target.value as typeof exportFormat)}
+              className="w-full px-3 py-2 border border-slate-300 rounded-lg focus:ring-2 focus:ring-primary-500"
+            >
+              <option value="generic">Generic JSON</option>
+              <option value="trocr">TrOCR Fine-Tuning</option>
+              <option value="llama_vision">Llama Vision Fine-Tuning</option>
+            </select>
+          </div>
+
+          <div>
+            <label className="block text-sm font-medium text-slate-700 mb-1">Session (optional)</label>
+            <select
+              value={selectedSession || ''}
+              onChange={(e) => setSelectedSession(e.target.value || null)}
+              className="w-full px-3 py-2 border border-slate-300 rounded-lg focus:ring-2 focus:ring-primary-500"
+            >
+              <option value="">Alle Sessions</option>
+              {sessions.map((session) => (
+                <option key={session.id} value={session.id}>{session.name}</option>
+              ))}
+            </select>
+          </div>
+
+          <button
+            onClick={handleExport}
+            disabled={exporting || (stats?.exportable_items || 0) === 0}
+            className="w-full px-4 py-2 bg-primary-600 text-white rounded-lg hover:bg-primary-700 disabled:opacity-50"
+          >
+            {exporting ? 'Exportiere...' : `${stats?.exportable_items || 0} Samples exportieren`}
+          </button>
+        </div>
+      </div>
+
+      {exportResult && (
+        <div className="bg-white rounded-lg shadow p-6">
+          <h3 className="text-lg font-semibold mb-4">Export-Ergebnis</h3>
+          <div className="bg-green-50 border border-green-200 rounded-lg p-4 mb-4">
+            <p className="text-green-800">
+              {exportResult.exported_count} Samples erfolgreich exportiert
+            </p>
+            <p className="text-sm text-green-600">
+              Batch: {exportResult.batch_id}
+            </p>
+          </div>
+          <div className="bg-slate-50 p-4 rounded-lg overflow-auto max-h-64">
+            <pre className="text-xs">{JSON.stringify(exportResult.samples?.slice(0, 3), null, 2)}</pre>
+            {(exportResult.samples?.length || 0) > 3 && (
+              <p className="text-slate-500 mt-2">... und {exportResult.samples.length - 3} weitere</p>
+            )}
+          </div>
+        </div>
+      )}
+    </div>
+  )
+}