feat: PaddleOCR Remote-Engine (PP-OCRv5 Latin auf Hetzner x86_64)

PaddleOCR als neue engine=paddle Option in der OCR-Pipeline.
Microservice auf Hetzner (paddleocr-service/), async HTTP-Client
(paddleocr_remote.py), Frontend-Dropdown, automatisch words_first.

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

admin-lehrer/components/ocr-pipeline/StepWordRecognition.tsx

@@ -60,7 +60,7 @@ export function StepWordRecognition({ sessionId, onNext, goToStep, skipHealGaps
   const [editedEntries, setEditedEntries] = useState<WordEntry[]>([])
   const [editedCells, setEditedCells] = useState<GridCell[]>([])
   const [mode, setMode] = useState<'overview' | 'labeling'>('overview')
-  const [ocrEngine, setOcrEngine] = useState<'auto' | 'tesseract' | 'rapid'>('auto')
+  const [ocrEngine, setOcrEngine] = useState<'auto' | 'tesseract' | 'rapid' | 'paddle'>('auto')
   const [usedEngine, setUsedEngine] = useState<string>('')
   const [pronunciation, setPronunciation] = useState<'british' | 'american'>('british')
   const [gridMethod, setGridMethod] = useState<'v2' | 'words_first'>('v2')
@@ -810,12 +810,13 @@ export function StepWordRecognition({ sessionId, onNext, goToStep, skipHealGaps
             {/* OCR Engine selector */}
             <select
               value={ocrEngine}
-              onChange={(e) => setOcrEngine(e.target.value as 'auto' | 'tesseract' | 'rapid')}
+              onChange={(e) => setOcrEngine(e.target.value as 'auto' | 'tesseract' | 'rapid' | 'paddle')}
               className="px-2 py-1.5 text-xs border rounded-lg dark:bg-gray-700 dark:border-gray-600"
             >
               <option value="auto">Auto (RapidOCR wenn verfuegbar)</option>
               <option value="rapid">RapidOCR (ONNX)</option>
               <option value="tesseract">Tesseract</option>
+              <option value="paddle">PaddleOCR (Hetzner)</option>
             </select>
 
             {/* Pronunciation selector (only for vocab) */}
@@ -843,6 +844,8 @@ export function StepWordRecognition({ sessionId, onNext, goToStep, skipHealGaps
               <span className={`px-2 py-0.5 rounded text-[10px] uppercase font-semibold ${
                 usedEngine === 'rapid'
                   ? 'bg-purple-100 dark:bg-purple-900/30 text-purple-700 dark:text-purple-300'
+                  : usedEngine === 'paddle'
+                  ? 'bg-blue-100 dark:bg-blue-900/30 text-blue-700 dark:text-blue-300'
                   : 'bg-gray-100 dark:bg-gray-700 text-gray-600 dark:text-gray-400'
               }`}>
                 {usedEngine}