feat: add Kombi-Modus (PaddleOCR + Tesseract) for OCR Overlay

Runs both OCR engines on the preprocessed image and merges results:
word boxes matched by IoU, coordinates averaged by confidence weight.
Unmatched Tesseract words (bullets, symbols) are added for better coverage.

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

admin-lehrer/app/(admin)/ai/ocr-overlay/page.tsx

@@ -11,12 +11,12 @@ import { StepRowDetection } from '@/components/ocr-pipeline/StepRowDetection'
 import { StepWordRecognition } from '@/components/ocr-pipeline/StepWordRecognition'
 import { OverlayReconstruction } from '@/components/ocr-overlay/OverlayReconstruction'
 import { PaddleDirectStep } from '@/components/ocr-overlay/PaddleDirectStep'
-import { OVERLAY_PIPELINE_STEPS, PADDLE_DIRECT_STEPS, DOCUMENT_CATEGORIES, dbStepToOverlayUi, type PipelineStep, type SessionListItem, type DocumentCategory } from './types'
+import { OVERLAY_PIPELINE_STEPS, PADDLE_DIRECT_STEPS, KOMBI_STEPS, DOCUMENT_CATEGORIES, dbStepToOverlayUi, type PipelineStep, type SessionListItem, type DocumentCategory } from './types'
 
 const KLAUSUR_API = '/klausur-api'
 
 export default function OcrOverlayPage() {
-  const [mode, setMode] = useState<'pipeline' | 'paddle-direct'>('pipeline')
+  const [mode, setMode] = useState<'pipeline' | 'paddle-direct' | 'kombi'>('pipeline')
   const [currentStep, setCurrentStep] = useState(0)
   const [sessionId, setSessionId] = useState<string | null>(null)
   const [sessionName, setSessionName] = useState<string>('')
@@ -63,13 +63,17 @@ export default function OcrOverlayPage() {
       setSessionName(data.name || data.filename || '')
       setActiveCategory(data.document_category || undefined)
 
-      // Check if this session was processed with paddle_direct
-      const isPaddleDirect = data.word_result?.ocr_engine === 'paddle_direct'
+      // Check if this session was processed with paddle_direct or kombi
+      const ocrEngine = data.word_result?.ocr_engine
+      const isPaddleDirect = ocrEngine === 'paddle_direct'
+      const isKombi = ocrEngine === 'kombi'
 
-      if (isPaddleDirect) {
-        setMode('paddle-direct')
+      if (isPaddleDirect || isKombi) {
+        const m = isKombi ? 'kombi' : 'paddle-direct'
+        const baseSteps = isKombi ? KOMBI_STEPS : PADDLE_DIRECT_STEPS
+        setMode(m)
         setSteps(
-          PADDLE_DIRECT_STEPS.map((s, i) => ({
+          baseSteps.map((s, i) => ({
             ...s,
             status: i < 4 ? 'completed' : i === 4 ? 'active' : 'pending',
           })),
@@ -101,7 +105,7 @@ export default function OcrOverlayPage() {
       if (sessionId === sid) {
         setSessionId(null)
         setCurrentStep(0)
-        const baseSteps = mode === 'paddle-direct' ? PADDLE_DIRECT_STEPS : OVERLAY_PIPELINE_STEPS
+        const baseSteps = mode === 'kombi' ? KOMBI_STEPS : mode === 'paddle-direct' ? PADDLE_DIRECT_STEPS : OVERLAY_PIPELINE_STEPS
         setSteps(baseSteps.map((s, i) => ({ ...s, status: i === 0 ? 'active' : 'pending' })))
       }
     } catch (e) {
@@ -158,7 +162,7 @@ export default function OcrOverlayPage() {
   const handleNext = () => {
     if (currentStep >= steps.length - 1) {
       // Last step completed — return to session list
-      const baseSteps = mode === 'paddle-direct' ? PADDLE_DIRECT_STEPS : OVERLAY_PIPELINE_STEPS
+      const baseSteps = mode === 'kombi' ? KOMBI_STEPS : mode === 'paddle-direct' ? PADDLE_DIRECT_STEPS : OVERLAY_PIPELINE_STEPS
       setSteps(baseSteps.map((s, i) => ({ ...s, status: i === 0 ? 'active' : 'pending' })))
       setCurrentStep(0)
       setSessionId(null)
@@ -187,7 +191,7 @@ export default function OcrOverlayPage() {
     setSessionId(null)
     setSessionName('')
     setCurrentStep(0)
-    const baseSteps = mode === 'paddle-direct' ? PADDLE_DIRECT_STEPS : OVERLAY_PIPELINE_STEPS
+    const baseSteps = mode === 'kombi' ? KOMBI_STEPS : mode === 'paddle-direct' ? PADDLE_DIRECT_STEPS : OVERLAY_PIPELINE_STEPS
     setSteps(baseSteps.map((s, i) => ({ ...s, status: i === 0 ? 'active' : 'pending' })))
   }
 
@@ -226,7 +230,7 @@ export default function OcrOverlayPage() {
   }, [sessionId, goToStep])
 
   const renderStep = () => {
-    if (mode === 'paddle-direct') {
+    if (mode === 'paddle-direct' || mode === 'kombi') {
       switch (currentStep) {
         case 0:
           return <StepOrientation sessionId={sessionId} onNext={handleOrientationComplete} />
@@ -237,7 +241,21 @@ export default function OcrOverlayPage() {
         case 3:
           return <StepCrop sessionId={sessionId} onNext={handleNext} />
         case 4:
-          return <PaddleDirectStep sessionId={sessionId} onNext={handleNext} />
+          return mode === 'kombi' ? (
+            <PaddleDirectStep
+              sessionId={sessionId}
+              onNext={handleNext}
+              endpoint="paddle-kombi"
+              title="Kombi-Modus"
+              description="PaddleOCR und Tesseract laufen parallel. Koordinaten werden gewichtet gemittelt fuer optimale Positionierung."
+              icon="🔀"
+              buttonLabel="Paddle + Tesseract starten"
+              runningLabel="Paddle + Tesseract laufen..."
+              engineKey="kombi"
+            />
+          ) : (
+            <PaddleDirectStep sessionId={sessionId} onNext={handleNext} />
+          )
         default:
           return null
       }
@@ -480,13 +498,29 @@ export default function OcrOverlayPage() {
         >
           Paddle Direct (5 Schritte)
         </button>
+        <button
+          onClick={() => {
+            if (mode === 'kombi') return
+            setMode('kombi')
+            setCurrentStep(0)
+            setSessionId(null)
+            setSteps(KOMBI_STEPS.map((s, i) => ({ ...s, status: i === 0 ? 'active' : 'pending' })))
+          }}
+          className={`px-3 py-1.5 text-xs font-medium rounded-md transition-colors ${
+            mode === 'kombi'
+              ? 'bg-white dark:bg-gray-700 text-gray-700 dark:text-gray-200 shadow-sm'
+              : 'text-gray-500 dark:text-gray-400 hover:text-gray-700 dark:hover:text-gray-300'
+          }`}
+        >
+          Kombi (5 Schritte)
+        </button>
       </div>
 
       <PipelineStepper
         steps={steps}
         currentStep={currentStep}
         onStepClick={handleStepClick}
-        onReprocess={mode === 'pipeline' && sessionId ? reprocessFromStep : undefined}
+        onReprocess={mode === 'pipeline' && sessionId != null ? reprocessFromStep : undefined}
       />
 
       <div className="min-h-[400px]">{renderStep()}</div>

admin-lehrer/app/(admin)/ai/ocr-overlay/types.ts

@@ -60,6 +60,18 @@ export const PADDLE_DIRECT_STEPS: PipelineStep[] = [
   { id: 'paddle-direct', name: 'PaddleOCR + Overlay', icon: '⚡', status: 'pending' },
 ]
 
+/**
+ * 5-step pipeline for Kombi mode (PaddleOCR + Tesseract).
+ * Same preprocessing, then both engines run and results are merged.
+ */
+export const KOMBI_STEPS: PipelineStep[] = [
+  { id: 'orientation', name: 'Orientierung', icon: '🔄', status: 'pending' },
+  { id: 'deskew', name: 'Begradigung', icon: '📐', status: 'pending' },
+  { id: 'dewarp', name: 'Entzerrung', icon: '🔧', status: 'pending' },
+  { id: 'crop', name: 'Zuschneiden', icon: '✂️', status: 'pending' },
+  { id: 'kombi', name: 'Paddle + Tesseract', icon: '🔀', status: 'pending' },
+]
+
 /** Map from DB step to overlay UI step index */
 export function dbStepToOverlayUi(dbStep: number): number {
   // DB: 1=start, 2=orient, 3=deskew, 4=dewarp, 5=crop, 6=columns, 7=rows, 8=words, 9=recon, 10=gt