feat: OCR pipeline step 8 — validation view with image detection & generation

Replaces the stub StepGroundTruth with a full side-by-side Original vs
Reconstruction view. Adds VLM-based image region detection (qwen2.5vl),
mflux image generation proxy, sync scroll/zoom, manual region drawing,
and score/notes persistence.

New backend endpoints: detect-images, generate-image, validate, get validation.
New standalone mflux-service (scripts/mflux-service.py) for Metal GPU generation.
Dockerfile.base: adds fonts-liberation (Apache-2.0).

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

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

@@ -313,7 +313,7 @@ export default function OcrPipelinePage() {
       case 6:
         return <StepReconstruction sessionId={sessionId} onNext={handleNext} />
       case 7:
-        return <StepGroundTruth />
+        return <StepGroundTruth sessionId={sessionId} onNext={handleNext} />
       default:
         return null
     }

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

@@ -264,6 +264,24 @@ export interface WordGroundTruth {
   notes?: string
 }
 
+export interface ImageRegion {
+  bbox_pct: { x: number; y: number; w: number; h: number }
+  prompt: string
+  description: string
+  image_b64: string | null
+  style: 'educational' | 'cartoon' | 'sketch' | 'clipart' | 'realistic'
+}
+
+export type ImageStyle = ImageRegion['style']
+
+export const IMAGE_STYLES: { value: ImageStyle; label: string }[] = [
+  { value: 'educational', label: 'Lehrbuch' },
+  { value: 'cartoon', label: 'Cartoon' },
+  { value: 'sketch', label: 'Skizze' },
+  { value: 'clipart', label: 'Clipart' },
+  { value: 'realistic', label: 'Realistisch' },
+]
+
 export const PIPELINE_STEPS: PipelineStep[] = [
   { id: 'deskew', name: 'Begradigung', icon: '📐', status: 'pending' },
   { id: 'dewarp', name: 'Entzerrung', icon: '🔧', status: 'pending' },

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

@@ -1,18 +1,582 @@
 'use client'
 
-export function StepGroundTruth() {
+import { useCallback, useEffect, useRef, useState } from 'react'
+import type {
+  GridCell, ColumnMeta, ImageRegion, ImageStyle,
+} from '@/app/(admin)/ai/ocr-pipeline/types'
+import { IMAGE_STYLES as STYLES } from '@/app/(admin)/ai/ocr-pipeline/types'
+
+const KLAUSUR_API = '/klausur-api'
+
+const COL_TYPE_COLORS: Record<string, string> = {
+  column_en: '#3b82f6',
+  column_de: '#22c55e',
+  column_example: '#f97316',
+  column_text: '#a855f7',
+  page_ref: '#06b6d4',
+  column_marker: '#6b7280',
+}
+
+interface StepGroundTruthProps {
+  sessionId: string | null
+  onNext: () => void
+}
+
+interface SessionData {
+  cells: GridCell[]
+  columnsUsed: ColumnMeta[]
+  imageWidth: number
+  imageHeight: number
+  originalImageUrl: string
+}
+
+export function StepGroundTruth({ sessionId, onNext }: StepGroundTruthProps) {
+  const [status, setStatus] = useState<'loading' | 'ready' | 'saving' | 'saved' | 'error'>('loading')
+  const [error, setError] = useState('')
+  const [session, setSession] = useState<SessionData | null>(null)
+  const [imageRegions, setImageRegions] = useState<(ImageRegion & { generating?: boolean })[]>([])
+  const [detecting, setDetecting] = useState(false)
+  const [zoom, setZoom] = useState(100)
+  const [syncScroll, setSyncScroll] = useState(true)
+  const [notes, setNotes] = useState('')
+  const [score, setScore] = useState<number | null>(null)
+  const [drawingRegion, setDrawingRegion] = useState(false)
+  const [dragStart, setDragStart] = useState<{ x: number; y: number } | null>(null)
+  const [dragEnd, setDragEnd] = useState<{ x: number; y: number } | null>(null)
+
+  const leftPanelRef = useRef<HTMLDivElement>(null)
+  const rightPanelRef = useRef<HTMLDivElement>(null)
+
+  // Load session data
+  useEffect(() => {
+    if (!sessionId) return
+    loadSessionData()
+  // eslint-disable-next-line react-hooks/exhaustive-deps
+  }, [sessionId])
+
+  const loadSessionData = async () => {
+    if (!sessionId) return
+    setStatus('loading')
+    try {
+      const resp = await fetch(`${KLAUSUR_API}/api/v1/ocr-pipeline/sessions/${sessionId}`)
+      if (!resp.ok) throw new Error(`Failed to load session: ${resp.status}`)
+      const data = await resp.json()
+
+      const wordResult = data.word_result || {}
+      setSession({
+        cells: wordResult.cells || [],
+        columnsUsed: wordResult.columns_used || [],
+        imageWidth: wordResult.image_width || data.image_width || 800,
+        imageHeight: wordResult.image_height || data.image_height || 600,
+        originalImageUrl: data.original_image_url || `${KLAUSUR_API}/api/v1/ocr-pipeline/sessions/${sessionId}/image/original`,
+      })
+
+      // Load existing validation data
+      const valResp = await fetch(`${KLAUSUR_API}/api/v1/ocr-pipeline/sessions/${sessionId}/reconstruction/validation`)
+      if (valResp.ok) {
+        const valData = await valResp.json()
+        const validation = valData.validation
+        if (validation) {
+          setImageRegions(validation.image_regions || [])
+          setNotes(validation.notes || '')
+          setScore(validation.score ?? null)
+        }
+      }
+
+      setStatus('ready')
+    } catch (e) {
+      setError(e instanceof Error ? e.message : String(e))
+      setStatus('error')
+    }
+  }
+
+  // Sync scroll between panels
+  const handleScroll = useCallback((source: 'left' | 'right') => {
+    if (!syncScroll) return
+    const from = source === 'left' ? leftPanelRef.current : rightPanelRef.current
+    const to = source === 'left' ? rightPanelRef.current : leftPanelRef.current
+    if (from && to) {
+      to.scrollTop = from.scrollTop
+      to.scrollLeft = from.scrollLeft
+    }
+  }, [syncScroll])
+
+  // Detect images via VLM
+  const handleDetectImages = async () => {
+    if (!sessionId) return
+    setDetecting(true)
+    try {
+      const resp = await fetch(
+        `${KLAUSUR_API}/api/v1/ocr-pipeline/sessions/${sessionId}/reconstruction/detect-images`,
+        { method: 'POST' }
+      )
+      if (!resp.ok) throw new Error(`Detection failed: ${resp.status}`)
+      const data = await resp.json()
+      setImageRegions(data.regions || [])
+    } catch (e) {
+      setError(e instanceof Error ? e.message : String(e))
+    } finally {
+      setDetecting(false)
+    }
+  }
+
+  // Generate image for a region
+  const handleGenerateImage = async (index: number) => {
+    if (!sessionId) return
+    const region = imageRegions[index]
+    if (!region) return
+
+    setImageRegions(prev => prev.map((r, i) => i === index ? { ...r, generating: true } : r))
+
+    try {
+      const resp = await fetch(
+        `${KLAUSUR_API}/api/v1/ocr-pipeline/sessions/${sessionId}/reconstruction/generate-image`,
+        {
+          method: 'POST',
+          headers: { 'Content-Type': 'application/json' },
+          body: JSON.stringify({
+            region_index: index,
+            prompt: region.prompt,
+            style: region.style,
+          }),
+        }
+      )
+      if (!resp.ok) throw new Error(`Generation failed: ${resp.status}`)
+      const data = await resp.json()
+
+      setImageRegions(prev => prev.map((r, i) =>
+        i === index ? { ...r, image_b64: data.image_b64, generating: false } : r
+      ))
+    } catch (e) {
+      setImageRegions(prev => prev.map((r, i) => i === index ? { ...r, generating: false } : r))
+      setError(e instanceof Error ? e.message : String(e))
+    }
+  }
+
+  // Save validation
+  const handleSave = async () => {
+    if (!sessionId) return
+    setStatus('saving')
+    try {
+      const resp = await fetch(
+        `${KLAUSUR_API}/api/v1/ocr-pipeline/sessions/${sessionId}/reconstruction/validate`,
+        {
+          method: 'POST',
+          headers: { 'Content-Type': 'application/json' },
+          body: JSON.stringify({ notes, score }),
+        }
+      )
+      if (!resp.ok) throw new Error(`Save failed: ${resp.status}`)
+      setStatus('saved')
+    } catch (e) {
+      setError(e instanceof Error ? e.message : String(e))
+      setStatus('error')
+    }
+  }
+
+  // Handle manual region drawing on reconstruction
+  const handleReconMouseDown = (e: React.MouseEvent<HTMLDivElement>) => {
+    if (!drawingRegion) return
+    const rect = e.currentTarget.getBoundingClientRect()
+    const x = ((e.clientX - rect.left) / rect.width) * 100
+    const y = ((e.clientY - rect.top) / rect.height) * 100
+    setDragStart({ x, y })
+    setDragEnd({ x, y })
+  }
+
+  const handleReconMouseMove = (e: React.MouseEvent<HTMLDivElement>) => {
+    if (!dragStart) return
+    const rect = e.currentTarget.getBoundingClientRect()
+    const x = ((e.clientX - rect.left) / rect.width) * 100
+    const y = ((e.clientY - rect.top) / rect.height) * 100
+    setDragEnd({ x, y })
+  }
+
+  const handleReconMouseUp = () => {
+    if (!dragStart || !dragEnd) return
+    const x = Math.min(dragStart.x, dragEnd.x)
+    const y = Math.min(dragStart.y, dragEnd.y)
+    const w = Math.abs(dragEnd.x - dragStart.x)
+    const h = Math.abs(dragEnd.y - dragStart.y)
+
+    if (w > 2 && h > 2) {
+      setImageRegions(prev => [...prev, {
+        bbox_pct: { x, y, w, h },
+        prompt: '',
+        description: 'Manually selected region',
+        image_b64: null,
+        style: 'educational' as ImageStyle,
+      }])
+    }
+
+    setDragStart(null)
+    setDragEnd(null)
+    setDrawingRegion(false)
+  }
+
+  const handleRemoveRegion = (index: number) => {
+    setImageRegions(prev => prev.filter((_, i) => i !== index))
+  }
+
+  if (status === 'loading') {
     return (
-    <div className="flex flex-col items-center justify-center py-16 text-center">
+      <div className="flex items-center justify-center py-16">
-      <div className="text-5xl mb-4">✅</div>
+        <div className="animate-spin rounded-full h-8 w-8 border-b-2 border-teal-500 mr-3" />
-      <h3 className="text-lg font-medium text-gray-700 dark:text-gray-300 mb-2">
+        <span className="text-gray-500 dark:text-gray-400">Session wird geladen...</span>
-        Schritt 7: Ground Truth Validierung
+      </div>
+    )
+  }
+
+  if (status === 'error' && !session) {
+    return (
+      <div className="text-center py-16">
+        <p className="text-red-500">{error}</p>
+        <button onClick={loadSessionData} className="mt-4 px-4 py-2 bg-teal-600 text-white rounded hover:bg-teal-700">
+          Erneut laden
+        </button>
+      </div>
+    )
+  }
+
+  if (!session) return null
+
+  const aspect = session.imageHeight / session.imageWidth
+
+  return (
+    <div className="space-y-4">
+      {/* Header / Controls */}
+      <div className="flex items-center justify-between flex-wrap gap-2">
+        <h3 className="text-lg font-medium text-gray-800 dark:text-gray-200">
+          Validierung — Original vs. Rekonstruktion
         </h3>
-      <p className="text-gray-500 dark:text-gray-400 max-w-md">
+        <div className="flex items-center gap-3">
-        Gesamtpruefung der rekonstruierten Seite gegen das Original.
+          <button
-        Dieser Schritt wird in einer zukuenftigen Version implementiert.
+            onClick={handleDetectImages}
-      </p>
+            disabled={detecting}
-      <div className="mt-6 px-4 py-2 bg-amber-100 dark:bg-amber-900/30 text-amber-700 dark:text-amber-400 rounded-full text-sm font-medium">
+            className="px-3 py-1.5 text-sm bg-indigo-600 text-white rounded hover:bg-indigo-700 disabled:opacity-50"
-        Kommt bald
+          >
+            {detecting ? 'Erkennung laeuft...' : 'Bilder erkennen'}
+          </button>
+          <label className="flex items-center gap-1.5 text-sm text-gray-600 dark:text-gray-400">
+            <input
+              type="checkbox"
+              checked={syncScroll}
+              onChange={e => setSyncScroll(e.target.checked)}
+              className="rounded"
+            />
+            Sync Scroll
+          </label>
+          <div className="flex items-center gap-1.5">
+            <button onClick={() => setZoom(z => Math.max(50, z - 25))} className="px-2 py-1 text-sm border rounded dark:border-gray-600 hover:bg-gray-100 dark:hover:bg-gray-700">-</button>
+            <span className="text-sm text-gray-600 dark:text-gray-400 w-12 text-center">{zoom}%</span>
+            <button onClick={() => setZoom(z => Math.min(200, z + 25))} className="px-2 py-1 text-sm border rounded dark:border-gray-600 hover:bg-gray-100 dark:hover:bg-gray-700">+</button>
+          </div>
+        </div>
+      </div>
+
+      {error && (
+        <div className="p-2 bg-red-50 dark:bg-red-900/20 text-red-600 dark:text-red-400 text-sm rounded">
+          {error}
+          <button onClick={() => setError('')} className="ml-2 underline">Schliessen</button>
+        </div>
+      )}
+
+      {/* Side-by-side panels */}
+      <div className="grid grid-cols-2 gap-4" style={{ height: 'calc(100vh - 380px)', minHeight: 400 }}>
+        {/* Left: Original */}
+        <div className="border rounded-lg dark:border-gray-700 overflow-hidden flex flex-col">
+          <div className="px-3 py-1.5 bg-gray-50 dark:bg-gray-800 text-sm font-medium text-gray-600 dark:text-gray-400 border-b dark:border-gray-700">
+            Original
+          </div>
+          <div
+            ref={leftPanelRef}
+            className="flex-1 overflow-auto"
+            onScroll={() => handleScroll('left')}
+          >
+            <div style={{ width: `${zoom}%`, minWidth: '100%' }}>
+              <img
+                src={session.originalImageUrl}
+                alt="Original"
+                className="w-full h-auto"
+                draggable={false}
+              />
+            </div>
+          </div>
+        </div>
+
+        {/* Right: Reconstruction */}
+        <div className="border rounded-lg dark:border-gray-700 overflow-hidden flex flex-col">
+          <div className="px-3 py-1.5 bg-gray-50 dark:bg-gray-800 text-sm font-medium text-gray-600 dark:text-gray-400 border-b dark:border-gray-700 flex items-center justify-between">
+            <span>Rekonstruktion</span>
+            <button
+              onClick={() => setDrawingRegion(!drawingRegion)}
+              className={`text-xs px-2 py-0.5 rounded ${drawingRegion ? 'bg-indigo-600 text-white' : 'bg-gray-200 dark:bg-gray-700 text-gray-600 dark:text-gray-400'}`}
+            >
+              {drawingRegion ? 'Region zeichnen...' : '+ Region'}
+            </button>
+          </div>
+          <div
+            ref={rightPanelRef}
+            className="flex-1 overflow-auto"
+            onScroll={() => handleScroll('right')}
+          >
+            <div style={{ width: `${zoom}%`, minWidth: '100%' }}>
+              {/* Reconstruction container */}
+              <div
+                className="relative bg-white"
+                style={{
+                  paddingBottom: `${aspect * 100}%`,
+                  cursor: drawingRegion ? 'crosshair' : 'default',
+                }}
+                onMouseDown={handleReconMouseDown}
+                onMouseMove={handleReconMouseMove}
+                onMouseUp={handleReconMouseUp}
+              >
+                {/* Column background stripes */}
+                {session.columnsUsed.map((col, i) => {
+                  const color = COL_TYPE_COLORS[col.type] || '#9ca3af'
+                  return (
+                    <div
+                      key={`col-${i}`}
+                      className="absolute top-0 bottom-0"
+                      style={{
+                        left: `${(col.x / session.imageWidth) * 100}%`,
+                        width: `${(col.width / session.imageWidth) * 100}%`,
+                        backgroundColor: color,
+                        opacity: 0.06,
+                      }}
+                    />
+                  )
+                })}
+
+                {/* Row separator lines — derive from cells */}
+                {(() => {
+                  const rowYs = new Set<number>()
+                  for (const cell of session.cells) {
+                    if (cell.col_index === 0 && cell.bbox_pct) {
+                      rowYs.add(cell.bbox_pct.y)
+                    }
+                  }
+                  return Array.from(rowYs).map((y, i) => (
+                    <div
+                      key={`row-${i}`}
+                      className="absolute left-0 right-0"
+                      style={{
+                        top: `${y}%`,
+                        height: '1px',
+                        backgroundColor: 'rgba(0,0,0,0.08)',
+                      }}
+                    />
+                  ))
+                })()}
+
+                {/* Cell texts */}
+                {session.cells.map(cell => {
+                  if (!cell.bbox_pct || !cell.text) return null
+                  const color = COL_TYPE_COLORS[cell.col_type] || '#374151'
+                  return (
+                    <span
+                      key={cell.cell_id}
+                      className="absolute text-[0.6em] leading-tight overflow-hidden"
+                      style={{
+                        left: `${cell.bbox_pct.x}%`,
+                        top: `${cell.bbox_pct.y}%`,
+                        width: `${cell.bbox_pct.w}%`,
+                        height: `${cell.bbox_pct.h}%`,
+                        color,
+                        fontFamily: "'Liberation Sans', 'DejaVu Sans', sans-serif",
+                        display: 'flex',
+                        alignItems: 'center',
+                        padding: '0 1px',
+                      }}
+                      title={`${cell.cell_id}: ${cell.text}`}
+                    >
+                      {cell.text}
+                    </span>
+                  )
+                })}
+
+                {/* Generated images at region positions */}
+                {imageRegions.map((region, i) => (
+                  <div
+                    key={`region-${i}`}
+                    className="absolute border-2 border-dashed border-indigo-400"
+                    style={{
+                      left: `${region.bbox_pct.x}%`,
+                      top: `${region.bbox_pct.y}%`,
+                      width: `${region.bbox_pct.w}%`,
+                      height: `${region.bbox_pct.h}%`,
+                    }}
+                  >
+                    {region.image_b64 ? (
+                      <img src={region.image_b64} alt={region.description} className="w-full h-full object-cover" />
+                    ) : (
+                      <div className="w-full h-full flex items-center justify-center bg-indigo-50/50 text-indigo-400 text-[0.5em]">
+                        {region.generating ? '...' : `Bild ${i + 1}`}
+                      </div>
+                    )}
+                  </div>
+                ))}
+
+                {/* Drawing rectangle */}
+                {dragStart && dragEnd && (
+                  <div
+                    className="absolute border-2 border-dashed border-red-500 bg-red-100/20 pointer-events-none"
+                    style={{
+                      left: `${Math.min(dragStart.x, dragEnd.x)}%`,
+                      top: `${Math.min(dragStart.y, dragEnd.y)}%`,
+                      width: `${Math.abs(dragEnd.x - dragStart.x)}%`,
+                      height: `${Math.abs(dragEnd.y - dragStart.y)}%`,
+                    }}
+                  />
+                )}
+              </div>
+            </div>
+          </div>
+        </div>
+      </div>
+
+      {/* Image regions panel */}
+      {imageRegions.length > 0 && (
+        <div className="border rounded-lg dark:border-gray-700 p-4">
+          <h4 className="text-sm font-medium text-gray-700 dark:text-gray-300 mb-3">
+            Bildbereiche ({imageRegions.length} gefunden)
+          </h4>
+          <div className="space-y-3">
+            {imageRegions.map((region, i) => (
+              <div key={i} className="flex items-start gap-3 p-3 bg-gray-50 dark:bg-gray-800 rounded-lg">
+                {/* Preview thumbnail */}
+                <div className="w-16 h-16 flex-shrink-0 border rounded dark:border-gray-600 overflow-hidden bg-white">
+                  {region.image_b64 ? (
+                    <img src={region.image_b64} alt="" className="w-full h-full object-cover" />
+                  ) : (
+                    <div className="w-full h-full flex items-center justify-center text-gray-400 text-xs">
+                      {Math.round(region.bbox_pct.w)}x{Math.round(region.bbox_pct.h)}%
+                    </div>
+                  )}
+                </div>
+
+                {/* Prompt + controls */}
+                <div className="flex-1 min-w-0 space-y-2">
+                  <div className="flex items-center gap-2">
+                    <span className="text-xs text-gray-500 dark:text-gray-400 flex-shrink-0">
+                      Bereich {i + 1}:
+                    </span>
+                    <input
+                      type="text"
+                      value={region.prompt}
+                      onChange={e => {
+                        setImageRegions(prev => prev.map((r, j) =>
+                          j === i ? { ...r, prompt: e.target.value } : r
+                        ))
+                      }}
+                      placeholder="Beschreibung / Prompt..."
+                      className="flex-1 text-sm px-2 py-1 border rounded dark:border-gray-600 dark:bg-gray-700 dark:text-white"
+                    />
+                  </div>
+                  <div className="flex items-center gap-2">
+                    <select
+                      value={region.style}
+                      onChange={e => {
+                        setImageRegions(prev => prev.map((r, j) =>
+                          j === i ? { ...r, style: e.target.value as ImageStyle } : r
+                        ))
+                      }}
+                      className="text-sm px-2 py-1 border rounded dark:border-gray-600 dark:bg-gray-700 dark:text-white"
+                    >
+                      {STYLES.map(s => (
+                        <option key={s.value} value={s.value}>{s.label}</option>
+                      ))}
+                    </select>
+                    <button
+                      onClick={() => handleGenerateImage(i)}
+                      disabled={!!region.generating || !region.prompt}
+                      className="px-3 py-1 text-sm bg-teal-600 text-white rounded hover:bg-teal-700 disabled:opacity-50"
+                    >
+                      {region.generating ? 'Generiere...' : 'Generieren'}
+                    </button>
+                    <button
+                      onClick={() => handleRemoveRegion(i)}
+                      className="px-2 py-1 text-sm text-red-600 hover:bg-red-50 dark:hover:bg-red-900/20 rounded"
+                    >
+                      Entfernen
+                    </button>
+                  </div>
+                  {region.description && region.description !== region.prompt && (
+                    <p className="text-xs text-gray-400">{region.description}</p>
+                  )}
+                </div>
+              </div>
+            ))}
+          </div>
+        </div>
+      )}
+
+      {/* Notes and score */}
+      <div className="border rounded-lg dark:border-gray-700 p-4 space-y-3">
+        <div className="flex items-center gap-4">
+          <label className="text-sm font-medium text-gray-700 dark:text-gray-300">
+            Bewertung (1-10):
+          </label>
+          <input
+            type="number"
+            min={1}
+            max={10}
+            value={score ?? ''}
+            onChange={e => setScore(e.target.value ? parseInt(e.target.value) : null)}
+            className="w-20 text-sm px-2 py-1 border rounded dark:border-gray-600 dark:bg-gray-700 dark:text-white"
+          />
+          <div className="flex gap-1">
+            {[1, 2, 3, 4, 5, 6, 7, 8, 9, 10].map(v => (
+              <button
+                key={v}
+                onClick={() => setScore(v)}
+                className={`w-7 h-7 text-xs rounded ${score === v ? 'bg-teal-600 text-white' : 'bg-gray-100 dark:bg-gray-700 text-gray-600 dark:text-gray-400 hover:bg-gray-200 dark:hover:bg-gray-600'}`}
+              >
+                {v}
+              </button>
+            ))}
+          </div>
+        </div>
+        <div>
+          <label className="text-sm font-medium text-gray-700 dark:text-gray-300 block mb-1">
+            Notizen:
+          </label>
+          <textarea
+            value={notes}
+            onChange={e => setNotes(e.target.value)}
+            rows={3}
+            placeholder="Anmerkungen zur Qualitaet der Rekonstruktion..."
+            className="w-full text-sm px-3 py-2 border rounded dark:border-gray-600 dark:bg-gray-700 dark:text-white"
+          />
+        </div>
+      </div>
+
+      {/* Actions */}
+      <div className="flex items-center justify-between">
+        <div className="text-sm text-gray-500 dark:text-gray-400">
+          {status === 'saved' && <span className="text-green-600 dark:text-green-400">Validierung gespeichert</span>}
+          {status === 'saving' && <span>Speichere...</span>}
+        </div>
+        <div className="flex items-center gap-3">
+          <button
+            onClick={handleSave}
+            disabled={status === 'saving'}
+            className="px-4 py-2 text-sm bg-gray-600 text-white rounded hover:bg-gray-700 disabled:opacity-50"
+          >
+            Speichern
+          </button>
+          <button
+            onClick={async () => {
+              await handleSave()
+              onNext()
+            }}
+            disabled={status === 'saving'}
+            className="px-4 py-2 text-sm bg-teal-600 text-white rounded hover:bg-teal-700 disabled:opacity-50"
+          >
+            Abschliessen
+          </button>
+        </div>
       </div>
     </div>
   )

docs-src/services/klausur-service/OCR-Pipeline.md

@@ -1,12 +1,12 @@
 # OCR Pipeline - Schrittweise Seitenrekonstruktion
 
-**Version:** 2.0.0
+**Version:** 3.0.0
 **Status:** Produktiv (Schritte 1–8 implementiert)
 **URL:** https://macmini:3002/ai/ocr-pipeline
 
 ## Uebersicht
 
-Die OCR Pipeline zerlegt den OCR-Prozess in **8 einzelne Schritte**, um eingescannte Vokabelseiten
+Die OCR Pipeline zerlegt den OCR-Prozess in **8 einzelne Schritte**, um eingescannte Seiten
 aus mehrspaltig gedruckten Schulbuechern Wort fuer Wort zu rekonstruieren.
 Jeder Schritt kann individuell geprueft, korrigiert und mit Ground-Truth-Daten versehen werden.
 
@@ -20,13 +20,94 @@ Jeder Schritt kann individuell geprueft, korrigiert und mit Ground-Truth-Daten v
 | 2 | Entzerrung (Dewarp) | Buchwoelbung entzerren (Vertikalkanten-Analyse) | Implementiert |
 | 3 | Spaltenerkennung | Unsichtbare Spalten finden (Projektionsprofile + Wortvalidierung) | Implementiert |
 | 4 | Zeilenerkennung | Horizontale Zeilen + Kopf-/Fusszeilen-Klassifikation + Luecken-Heilung | Implementiert |
-| 5 | Worterkennung | Grid aus Spalten x Zeilen, OCR pro Zelle, Post-Processing | Implementiert |
+| 5 | Worterkennung | Hybrid-Grid: Breite Spalten full-page, schmale cell-crop | Implementiert |
 | 6 | Korrektur | Zeichenverwirrung + regel-basierte Rechtschreibkorrektur (SSE-Stream) | Implementiert |
-| 7 | Rekonstruktion | Interaktive Zellenbearbeitung auf Bildhintergrund | Implementiert |
+| 7 | Rekonstruktion | Interaktive Zellenbearbeitung auf Bildhintergrund (Fabric.js) | Implementiert |
 | 8 | Validierung | Ground-Truth-Vergleich und Qualitaetspruefung | Implementiert |
 
 ---
 
+## Dokumenttyp-Erkennung und Pipeline-Pfade
+
+### Automatische Weiche: `detect_document_type()`
+
+Nicht jedes Dokument durchlaeuft denselben Pfad. Nach den gemeinsamen Vorverarbeitungsschritten
+(Deskew, Dewarp, Binarisierung) analysiert `detect_document_type()` die Seitenstruktur
+**ohne OCR** — rein ueber Projektionsprofile und Textdichte-Analyse (< 2 Sekunden).
+
+```
+detect_document_type(ocr_img, img_bgr) → DocumentTypeResult
+```
+
+#### Entscheidungslogik
+
+```mermaid
+flowchart TD
+    A[Bild-Input] --> B[Vertikales Projektionsprofil]
+    B --> C{Interne Spalten-Gaps >= 2?}
+    C -->|Ja| D{Zeilen-Gaps >= 5?}
+    D -->|Ja| E["vocab_table<br/>pipeline = cell_first<br/>confidence 0.7–0.95"]
+    D -->|Nein| F{Zeilen-Gaps >= 3?}
+    C -->|Nein| G{Interne Spalten-Gaps >= 1?}
+    G -->|Ja| F
+    G -->|Nein| H["full_text<br/>pipeline = full_page<br/>skip: columns, rows"]
+    F -->|Ja| I["generic_table<br/>pipeline = cell_first<br/>confidence 0.5–0.85"]
+    F -->|Nein| H
+```
+
+| Dokumenttyp | Spalten-Gaps | Zeilen-Gaps | Pipeline | Beispiel |
+|-------------|-------------|-------------|----------|----------|
+| `vocab_table` | ≥ 2 | ≥ 5 | `cell_first` | 3-spaltige Schulbuch-Vokabeltabelle |
+| `generic_table` | ≥ 1 | ≥ 3 | `cell_first` | 2-spaltiges Glossar |
+| `full_text` | 0 | egal | `full_page` | Fliesstext, Aufsatz, Buchseite |
+
+### Komplett-Flussdiagramm
+
+```
+┌─────────────────────────────────────────────────────────────────────┐
+│ GEMEINSAME VORVERARBEITUNG (alle Dokumente)                         │
+│                                                                     │
+│ Stage 1: Render (432 DPI, 3× Zoom)                                 │
+│ Stage 2: Deskew (Hough Lines + Ensemble)                            │
+│ Stage 3: Dewarp (Vertikalkanten-Drift, Ensemble Shear)              │
+│ Stage 4: Dual-Bild (ocr_img = binarisiert, layout_img = CLAHE)     │
+└─────────────────────────────────────┬───────────────────────────────┘
+                                      │
+                            detect_document_type()
+                                      │
+                    ┌─────────────────┴──────────────────┐
+                    ▼                                     ▼
+            FULL-TEXT PFAD                        CELL-FIRST PFAD
+            (pipeline='full_page')                (pipeline='cell_first')
+                    │                                     │
+            Keine Spalten/Zeilen                  Spaltenerkennung
+            analyze_layout_by_words()             detect_column_geometry()
+            Lese-Reihenfolge                      _detect_sub_columns()
+                    │                             expand_narrow_columns()
+                    │                             Zeilenerkennung
+                    │                             detect_row_geometry()
+                    │                                     │
+                    │                            build_cell_grid_v2()
+                    │                                     │
+                    │                           ┌─────────┴──────────┐
+                    │                           ▼                    ▼
+                    │                     Breite Spalten       Schmale Spalten
+                    │                     (>= 15% Breite)     (< 15% Breite)
+                    │                     Full-Page Words     Cell-Crop OCR
+                    │                     word_lookup          cell_crop_v2
+                    │                           │                    │
+                    └───────────────────────────┴────────────────────┘
+                                                │
+                                    Post-Processing Pipeline
+                                    (Lautschrift, Komma-Split, etc.)
+                                                │
+                                    Schritt 6: Korrektur (Spell)
+                                    Schritt 7: Rekonstruktion
+                                    Schritt 8: Validierung
+```
+
+---
+
 ## Architektur
 
 ```
@@ -55,9 +136,11 @@ Admin-Lehrer (Next.js)          klausur-service (FastAPI :8086)
 
 ```
 klausur-service/backend/
+├── services/
+│   └── cv_vocab_pipeline.py            # Computer Vision + NLP Algorithmen
 ├── ocr_pipeline_api.py                 # FastAPI Router (alle Endpoints)
 ├── ocr_pipeline_session_store.py       # PostgreSQL Persistence
-├── cv_vocab_pipeline.py             # Computer Vision + NLP Algorithmen
+├── layout_reconstruction_service.py    # Fabric.js JSON + PDF/DOCX Export
 └── migrations/
     ├── 002_ocr_pipeline_sessions.sql   # Basis-Schema
     ├── 003_add_row_result.sql          # Row-Result Spalte
@@ -76,6 +159,7 @@ admin-lehrer/
     ├── StepWordRecognition.tsx          # Schritt 5: Worterkennung
     ├── StepLlmReview.tsx               # Schritt 6: Korrektur (SSE-Stream)
     ├── StepReconstruction.tsx           # Schritt 7: Rekonstruktion (Canvas)
+    ├── FabricReconstructionCanvas.tsx   # Fabric.js Editor
     └── StepGroundTruth.tsx             # Schritt 8: Validierung
 ```
 
@@ -94,6 +178,7 @@ Alle Endpoints unter `/api/v1/ocr-pipeline/`.
 | `GET` | `/sessions/{id}` | Session-Info mit allen Step-Results |
 | `PUT` | `/sessions/{id}` | Session umbenennen |
 | `DELETE` | `/sessions/{id}` | Session loeschen |
+| `POST` | `/sessions/{id}/detect-type` | Dokumenttyp erkennen |
 
 ### Bilder
 
@@ -160,6 +245,34 @@ Alle Endpoints unter `/api/v1/ocr-pipeline/`.
 | Methode | Pfad | Beschreibung |
 |---------|------|--------------|
 | `POST` | `/sessions/{id}/reconstruction` | Zellaenderungen speichern |
+| `GET` | `/sessions/{id}/reconstruction/fabric-json` | Fabric.js Canvas-Daten |
+| `GET` | `/sessions/{id}/reconstruction/export/pdf` | PDF-Export (reportlab) |
+| `GET` | `/sessions/{id}/reconstruction/export/docx` | DOCX-Export (python-docx) |
+| `POST` | `/sessions/{id}/reconstruction/detect-images` | Bildbereiche per VLM erkennen |
+| `POST` | `/sessions/{id}/reconstruction/generate-image` | Bild per mflux generieren |
+| `POST` | `/sessions/{id}/reconstruction/validate` | Validierung speichern (Step 8) |
+| `GET` | `/sessions/{id}/reconstruction/validation` | Validierungsdaten abrufen |
+
+---
+
+## Schritt 2: Entzerrung/Dewarp (Detail)
+
+### Algorithmus: Vertikalkanten-Drift
+
+Die Dewarp-Erkennung misst die **vertikale Spaltenkippung** (dx/dy) statt Textzeilen-Neigung:
+
+1. Woerter werden nach X-Position in vertikale Spaltencluster gruppiert
+2. Pro Cluster: Lineare Regression `x = a*y + b` → `a = dx/dy = tan(shear_angle)`
+3. Ensemble aus drei Methoden: Textzeilen (1.5× Gewicht), Projektionsprofil (2-Pass), Vertikalkanten
+4. Qualitaetspruefung: Horizontale Projektionsvarianz vor/nach Korrektur
+
+**Schwellenwerte:**
+
+| Parameter | Wert | Beschreibung |
+|-----------|------|--------------|
+| Min. Korrekturwinkel | 0.08° | Unter 0.08° wird nicht korrigiert |
+| Ensemble Min-Confidence | 0.35 | Mindest-Konfidenz fuer Korrektur |
+| Quality-Gate Skip | < 0.5° | Kleine Korrekturen ueberspringen Quality-Gate |
 
 ---
 
@@ -180,6 +293,38 @@ Bild → Binarisierung → Vertikalprofil → Lueckenerkennung → Wort-Validier
 - **Phantom-Spalten-Filter (Step 9):** Spalten mit Breite < 3 % der Content-Breite UND < 3 Woerter werden als Artefakte entfernt; die angrenzenden Spalten schliessen die Luecke.
 - **Spaltenzuweisung:** Woerter werden anhand des groessten horizontalen Ueberlappungsbereichs einer Spalte zugeordnet.
 
+### Sub-Spalten-Erkennung: `_detect_sub_columns()`
+
+Erkennt versteckte Sub-Spalten innerhalb breiter Spalten (z.B. Seitenzahl-Spalte links neben EN-Vokabeln).
+
+**Algorithmus (Left-Edge Alignment Clustering):**
+
+1. Fuer jede Spalte mit `width_ratio >= 0.15` und `word_count >= 5`:
+2. Left-Edges aller Woerter mit `conf >= 30` sammeln
+3. In Alignment-Bins clustern (8px Toleranz)
+4. Linkester Bin mit >= 10% der Woerter = wahrer Spaltenanfang
+5. Woerter links davon = Sub-Spalte, wenn >= 2 und < 35% Anteil
+6. Neue ColumnGeometry-Objekte mit korrekten Indizes erzeugen
+
+**Koordinatensystem:** Word `left`-Werte sind relativ zum Content-ROI (`left_x`), `ColumnGeometry.x` ist absolut. `left_x` wird als Parameter durchgereicht.
+
+### Spalten-Erweiterung: `expand_narrow_columns()`
+
+Laeuft **nach** `_detect_sub_columns()`. Erweitert sehr schmale Spalten (< 10% Content-Breite,
+z.B. `page_ref`, `marker`) in den Weissraum zum Nachbar-Spalte hinein, aber nie ueber die
+naechsten Woerter im Nachbarn hinaus (4px Sicherheitsabstand).
+
+### Spaltentyp-Klassifikation: `classify_column_types()`
+
+| Spaltentyp | Beschreibung | Erkennung |
+|------------|--------------|-----------|
+| `column_en` | Englische Vokabeln | EN-Funktionswoerter (the, a, is...) |
+| `column_de` | Deutsche Uebersetzung | DE-Funktionswoerter (der, die, das...) |
+| `column_example` | Beispielsaetze | Abkuerzungen, Grammatik-Marker |
+| `page_ref` | Seitenzahlen | Schmal (< 20% Breite), wenige Woerter |
+| `column_marker` | Dekorative Markierungen | Sehr schmal, spezielle Zeichen |
+| `column_text` | Generischer Text | Fallback |
+
 ### Konfigurierbare Parameter
 
 ```python
@@ -219,29 +364,95 @@ def _heal_row_gaps(rows, top_bound, bottom_bound):
 
 ---
 
-## Schritt 5: Worterkennung (Detail)
+## Schritt 5: Worterkennung — Hybrid-Grid (Detail)
 
-### Algorithmus: `build_cell_grid()`
+### Algorithmus: `build_cell_grid_v2()`
 
-Schritt 5 nutzt die Ergebnisse von Schritt 3 (Spalten) und Schritt 4 (Zeilen), um ein Grid
+Schritt 5 nutzt eine **Hybrid-Strategie**: Breite Spalten verwenden die Full-Page-Tesseract-Woerter,
-zu erstellen und jede Zelle per OCR auszulesen.
+schmale Spalten werden isoliert per Cell-Crop OCR verarbeitet.
 
-```
+!!! success "Warum Hybrid?"
-Spalten (Step 3):    column_en  |  column_de  |  column_example
+    Full-Page OCR liefert gute Ergebnisse fuer breite Spalten (Saetze, IPA-Klammern, Interpunktion).
-                     ───────────┼─────────────┼────────────────
+    Aber bei schmalen Spalten (Seitenzahlen, Marker) „bluten" Woerter aus Nachbar-Spalten ein.
-Zeilen (Step 4):  R0 │  hello   │  hallo      │  Hello, World!
+    Cell-Crop isoliert jede Zelle und verhindert dieses Bleeding.
-                  R1 │  world   │  Welt       │  The whole world
+
-                  R2 │  book    │  Buch       │  Read a book
+### Broad vs. Narrow — Die 15%-Schwelle
-                     ───────────┼─────────────┼────────────────
+
+```python
+_NARROW_COL_THRESHOLD_PCT = 15.0  # cv_vocab_pipeline.py
 ```
 
-**Ablauf:**
+| Eigenschaft | Breite Spalten (>= 15%) | Schmale Spalten (< 15%) |
+|-------------|------------------------|------------------------|
+| **OCR-Quelle** | Full-Page Tesseract (vorher gelaufen) | Isolierter Cell-Crop |
+| **Wort-Zuweisung** | `_assign_row_words_to_columns()` | Direktes Zell-OCR |
+| **Confidence-Filter** | `conf >= 30` | `conf >= 30` |
+| **Text-Bereinigung** | `_clean_cell_text()` (mittel) | `_clean_cell_text_lite()` (aggressiv) |
+| **Neighbour-Bleeding** | Risiko vorhanden | Verhindert (isoliert) |
+| **Parallelisierung** | Sequentiell | Parallel (`max_workers=4`) |
+| **OCR-Engine Label** | `word_lookup` | `cell_crop_v2` |
+| **Typische Spalten** | EN-Vokabeln, DE-Uebersetzung, Beispielsaetze | Seitenzahlen, Marker |
 
-1. **Initialer Scan:** Ganzes Bild einmal per Tesseract/RapidOCR → alle Wort-Bboxes
+**Empirische Grundlage:** Typische breite Spalten liegen bei 20–40% Bildbreite,
-2. **Zuweisung:** Jedes Wort der Spalte mit groesstem horizontalem Ueberlapp zuordnen
+typische schmale bei 3–12%. Die 15%-Grenze trennt diese Gruppen sauber.
-3. **Zell-OCR Fallback:** Leere Zellen bekommen eigenen Crop + erneuten OCR-Aufruf (PSM 6/7)
+
-4. **Batch-Spalten-OCR:** Bei vielen leeren Zellen in einer Spalte: gesamte Spalte einmal OCR-en
+!!! note "Offener Punkt: Schwellen-Validierung"
-5. **Post-Processing:** Continuation-Rows zusammenfuehren, Lautschrift erkennen, Komma-Eintraege splitten
+    Die 15%-Schwelle wurde an Vokabeltabellen mit 3–5 Spalten validiert.
+    Fuer eine breitere Validierung werden diverse Schulbuchseiten mit unterschiedlichen
+    Layouts (2-, 3-, 4-, 5-spaltig, verschiedene Verlage) benoetigt. Aktuell gibt es
+    in der Datenbank nur Sessions mit demselben Arbeitsblatt-Typ.
+
+### Cell-Crop OCR: `_ocr_cell_crop()`
+
+Isolierte OCR einer einzelnen Zelle (Spalte × Zeile Schnittflaeche):
+
+1. **Crop:** Exakte Spalten- × Zeilengrenzen mit 3px internem Padding
+2. **Density-Check:** Ueberspringe leere Zellen (`dark_ratio < 0.005`)
+3. **Upscaling:** Kleine Crops (Hoehe < 80px) werden 3× vergroessert
+4. **OCR:** Engine-spezifisch (Tesseract, TrOCR, RapidOCR, LightON)
+5. **Fallback:** Bei leerem Ergebnis → PSM 7 (Einzelzeile) statt PSM 6
+6. **Bereinigung:** `_clean_cell_text_lite()` (aggressives Noise-Filtering)
+
+### Ablauf von `build_cell_grid_v2()`
+
+```
+Eingabe: ocr_img, column_regions, row_geometries
+                    │
+        ┌───────────┴───────────┐
+        │ Filter                 │
+        │ • Phantom-Zeilen       │
+        │ • Artefakt-Zeilen      │
+        │ • Irrelevante Spalten  │
+        │   (header, footer,     │
+        │    margin, ignore)     │
+        └───────────┬───────────┘
+                    │
+        ┌───────────┴───────────┐
+        │ Klassifizierung        │
+        │ Spalte.width / img_w   │
+        │ >= 15% → broad         │
+        │ < 15%  → narrow        │
+        └───────────┬───────────┘
+                    │
+        ┌───────────┴────────────────┐
+        │                            │
+   Phase 1: Broad               Phase 2: Narrow
+   (sequentiell)                 (parallel, max_workers=4)
+        │                            │
+   Pro (row, col):               Pro (row, col):
+   1. Words aus Full-Page        1. _ocr_cell_crop()
+   2. Filter conf >= 30         2. Isoliertes Zell-Bild
+   3. _words_to_reading_order   3. Upscale wenn noetig
+   4. _clean_cell_text()        4. _clean_cell_text_lite()
+        │                            │
+        └───────────┬────────────────┘
+                    │
+            Merge + Sortierung
+            (row_index, col_index)
+            Leere Zeilen entfernen
+                    │
+               Ausgabe: cells[], columns_meta[]
+```
 
 ### Post-Processing Pipeline (in `build_vocab_pipeline_streaming`)
 
@@ -264,7 +475,7 @@ Zeilen (Step 4):  R0 │  hello   │  hallo      │  Hello, World!
 
 ### Korrektur-Engine
 
-Schritt 6 kombiniert zwei Korrektur-Stufen, beide als SSE-Stream:
+Schritt 6 kombiniert drei Korrektur-Stufen, alle als SSE-Stream:
 
 **Stufe 1 — Zeichenverwirrungskorrektur** (`_fix_character_confusion`):
 
@@ -288,8 +499,9 @@ _SPELL_SUBS = {
 }
 ```
 
-Logik: Kandidaten werden durch Woerterbuch-Lookup validiert. Strukturregel: Verdaechtiges
+**Stufe 3 — Seitenzahl-Korrektur** (`page_ref`-Felder):
-Zeichen an Position 0 + Rest klein → erstes Substitut (z.B. `8en` → `Ben`).
+
+Korrigiert haeufige OCR-Fehler in Seitenverweisen (z.B. `p.5g` → `p.59`).
 
 ### Umgebungsvariablen
 
@@ -318,7 +530,11 @@ Change-Format:
 
 ## Schritt 7: Rekonstruktion (Detail)
 
-Interaktiver Canvas-Editor: Das entzerrte Originalbild wird mit 30 % Opazitaet als Hintergrund
+Zwei Modi verfuegbar:
+
+### Einfacher Modus
+
+Das entzerrte Originalbild wird mit 30 % Opazitaet als Hintergrund
 angezeigt, alle Grid-Zellen (auch leere!) werden als editierbare Textfelder darueber gelegt.
 
 **Features:**
@@ -331,6 +547,14 @@ angezeigt, alle Grid-Zellen (auch leere!) werden als editierbare Textfelder daru
 - Zoom 50–200 %
 - Per-Zell-Reset-Button bei geaenderten Zellen
 
+### Fabric.js Editor
+
+Erweiterter Canvas-Editor (`FabricReconstructionCanvas.tsx`):
+
+- Drag & Drop fuer Zellen
+- Freie Positionierung auf dem Canvas
+- Export als PDF (reportlab) oder DOCX (python-docx)
+
 ```
 POST /sessions/{id}/reconstruction
 Body: {"cells": [{"cell_id": "r5_c2", "text": "corrected text"}]}
@@ -338,6 +562,19 @@ Body: {"cells": [{"cell_id": "r5_c2", "text": "corrected text"}]}
 
 ---
 
+## Wichtige Konstanten
+
+| Konstante | Wert | Datei | Beschreibung |
+|-----------|------|-------|--------------|
+| `_NARROW_COL_THRESHOLD_PCT` | 15.0% | cv_vocab_pipeline.py | Schwelle breit/schmal fuer Hybrid-OCR |
+| `_NARROW_THRESHOLD_PCT` | 10.0% | cv_vocab_pipeline.py | Schwelle fuer Spalten-Erweiterung |
+| `_MIN_WORD_CONF` | 30 | cv_vocab_pipeline.py | Mindest-Confidence fuer OCR-Woerter |
+| `_PAD` | 3px | cv_vocab_pipeline.py | Internes Padding bei Cell-Crop |
+| `PDF_ZOOM` | 3.0 | cv_vocab_pipeline.py | PDF-Rendering (= 432 DPI) |
+| `_MIN_WORD_MARGIN` | 4px | cv_vocab_pipeline.py | Sicherheitsabstand bei Spalten-Erweiterung |
+
+---
+
 ## Datenbank-Schema
 
 ```sql
@@ -348,6 +585,10 @@ CREATE TABLE ocr_pipeline_sessions (
     status VARCHAR(50) DEFAULT 'active',
     current_step INT DEFAULT 1,
 
+    -- Dokumenttyp-Erkennung
+    doc_type VARCHAR(50),        -- 'vocab_table', 'generic_table', 'full_text'
+    doc_type_result JSONB,       -- Vollstaendiges DetectionResult
+
     -- Bilder (BYTEA)
     original_png BYTEA,
     deskewed_png BYTEA,
@@ -374,7 +615,7 @@ CREATE TABLE ocr_pipeline_sessions (
 ```json
 {
   "vocab_entries": [...],
-  "cells": [{"cell_id": "r0_c0", "text": "hello", "bbox_pct": {...}, ...}],
+  "cells": [{"cell_id": "r0_c0", "text": "hello", "bbox_pct": {...}, "ocr_engine": "word_lookup", ...}],
   "columns_used": [...],
   "llm_review": {
     "changes": [{"row_index": 5, "field": "english", "old": "...", "new": "..."}],
@@ -399,10 +640,13 @@ CREATE TABLE ocr_pipeline_sessions (
 | `onnxruntime` | latest | MIT | ONNX-Inferenz fuer RapidOCR |
 | `pyspellchecker` | ≥0.8.1 | MIT | Regel-basierte OCR-Korrektur (Schritt 6) |
 | `eng-to-ipa` | latest | MIT | IPA-Lautschrift-Lookup (Schritt 5) |
+| `reportlab` | latest | BSD | PDF-Export (Schritt 7) |
+| `python-docx` | ≥1.1.0 | MIT | DOCX-Export (Schritt 7) |
+| `fabric` (JS) | ^6 | MIT | Canvas-Editor (Frontend) |
 
 !!! info "pyspellchecker (neu seit 2026-03)"
     `pyspellchecker` (MIT-Lizenz) ersetzt die LLM-basierte Korrektur als Standard-Engine.
-    EN+DE-Woerterbuch, ~134k Woerter. Kein Ollama notig.
+    EN+DE-Woerterbuch, ~134k Woerter. Kein Ollama noetig.
     Umschaltbar via `REVIEW_ENGINE=llm` fuer den LLM-Pfad.
 
 ---
@@ -413,8 +657,10 @@ CREATE TABLE ocr_pipeline_sessions (
 |---------|---------|------------|
 | Schraeg gedruckte Seiten | Deskew erkennt Text-Rotation, nicht Seiten-Rotation | Manueller Winkel |
 | Sehr kleine Schrift (< 8pt) | Tesseract PSM 7 braucht min. Zeichengroesse | Vorher zoomen |
-| Handgeschriebene Eintraege | Tesseract/RapidOCR sind fuer Druckschrift optimiert | TrOCR-Engine (geplant) |
+| Handgeschriebene Eintraege | Tesseract/RapidOCR sind fuer Druckschrift optimiert | TrOCR-Engine |
 | Mehr als 4 Spalten | Projektionsprofil kann verschmelzen | Manuelle Spalten |
+| Farbige Marker (rot/blau) | HSV-Erkennung erzeugt False Positives | Manuell im Rekonstruktions-Editor |
+| 15%-Schwelle nicht breit validiert | Nur an einem Arbeitsblatt-Typ getestet | Diverse Schulbuchseiten testen |
 
 ---
 
@@ -425,17 +671,15 @@ CREATE TABLE ocr_pipeline_sessions (
 git push origin main
 
 # 2. Mac Mini pull + build
-ssh macmini "cd /Users/benjaminadmin/Projekte/breakpilot-lehrer && git pull --no-rebase origin main"
+ssh macmini "git -C /Users/benjaminadmin/Projekte/breakpilot-lehrer pull --no-rebase origin main"
 
-# klausur-service (Backend) — bei requirements.txt Aenderungen: klausur-base neu bauen
+# klausur-service (Backend)
-ssh macmini "cd /Users/benjaminadmin/Projekte/breakpilot-lehrer && \
+ssh macmini "/usr/local/bin/docker compose -f /Users/benjaminadmin/Projekte/breakpilot-lehrer/docker-compose.yml build klausur-service"
-  /usr/local/bin/docker compose build klausur-service && \
+ssh macmini "/usr/local/bin/docker compose -f /Users/benjaminadmin/Projekte/breakpilot-lehrer/docker-compose.yml up -d klausur-service"
-  /usr/local/bin/docker compose up -d klausur-service"
 
 # admin-lehrer (Frontend)
-ssh macmini "cd /Users/benjaminadmin/Projekte/breakpilot-lehrer && \
+ssh macmini "/usr/local/bin/docker compose -f /Users/benjaminadmin/Projekte/breakpilot-lehrer/docker-compose.yml build admin-lehrer"
-  /usr/local/bin/docker compose build admin-lehrer && \
+ssh macmini "/usr/local/bin/docker compose -f /Users/benjaminadmin/Projekte/breakpilot-lehrer/docker-compose.yml up -d admin-lehrer"
-  /usr/local/bin/docker compose up -d admin-lehrer"
 
 # 3. Testen unter:
 # https://macmini:3002/ai/ocr-pipeline
@@ -445,9 +689,8 @@ ssh macmini "cd /Users/benjaminadmin/Projekte/breakpilot-lehrer && \
     Wenn `requirements.txt` geaendert wird (z.B. neues Paket hinzugefuegt), muss zuerst
     das Base-Image neu gebaut werden:
     ```bash
-    ssh macmini "cd ~/Projekte/breakpilot-lehrer && \
+    ssh macmini "/usr/local/bin/docker build -f /Users/benjaminadmin/Projekte/breakpilot-lehrer/klausur-service/Dockerfile.base \
-      /usr/local/bin/docker build -f klausur-service/Dockerfile.base \
+      -t klausur-base:latest /Users/benjaminadmin/Projekte/breakpilot-lehrer/klausur-service/"
-      -t klausur-base:latest klausur-service/"
     ```
 
 ---
@@ -456,6 +699,9 @@ ssh macmini "cd /Users/benjaminadmin/Projekte/breakpilot-lehrer && \
 
 | Datum | Version | Aenderung |
 |-------|---------|----------|
+| 2026-03-05 | 3.0.0 | Doku-Update: Dokumenttyp-Erkennung, Hybrid-Grid, Sub-Column-Detection, Pipeline-Pfade |
+| 2026-03-04 | 2.2.0 | Dewarp: Vertikalkanten-Drift statt Textzeilen-Neigung, Schwellenwerte gesenkt |
+| 2026-03-04 | 2.1.0 | Sub-Column-Detection, expand_narrow_columns, Fabric.js Editor, PDF/DOCX-Export |
 | 2026-03-03 | 2.0.0 | Schritte 6–7 implementiert; Spell-Checker, Rekonstruktions-Canvas |
 | 2026-03-03 | 1.5.0 | Spaltenerkennung: volle Bildbreite fuer initialen Scan, Phantom-Filter |
 | 2026-03-03 | 1.4.0 | Zeilenerkennung: Artefakt-Zeilen entfernen + Luecken-Heilung |

klausur-service/Dockerfile.base

@@ -16,6 +16,7 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
     tesseract-ocr-eng \
     libgl1 \
     libglib2.0-0 \
+    fonts-liberation \
     && rm -rf /var/lib/apt/lists/*
 
 # Python dependencies

klausur-service/backend/ocr_pipeline_api.py

@@ -2238,6 +2238,271 @@ async def export_reconstruction_docx(session_id: str):
         raise HTTPException(status_code=501, detail="python-docx not installed")
 
 
+# ---------------------------------------------------------------------------
+# Step 8: Validation — Original vs. Reconstruction
+# ---------------------------------------------------------------------------
+
+STYLE_SUFFIXES = {
+    "educational": "educational illustration, textbook style, clear, colorful",
+    "cartoon": "cartoon, child-friendly, simple shapes",
+    "sketch": "pencil sketch, hand-drawn, black and white",
+    "clipart": "clipart, flat vector style, simple",
+    "realistic": "photorealistic, high detail",
+}
+
+
+class ValidationRequest(BaseModel):
+    notes: Optional[str] = None
+    score: Optional[int] = None
+
+
+class GenerateImageRequest(BaseModel):
+    region_index: int
+    prompt: str
+    style: str = "educational"
+
+
+@router.post("/sessions/{session_id}/reconstruction/detect-images")
+async def detect_image_regions(session_id: str):
+    """Detect illustration/image regions in the original scan using VLM.
+
+    Sends the original image to qwen2.5vl to find non-text, non-table
+    image areas, returning bounding boxes (in %) and descriptions.
+    """
+    import base64
+    import httpx
+    import re
+
+    session = await get_session_db(session_id)
+    if not session:
+        raise HTTPException(status_code=404, detail=f"Session {session_id} not found")
+
+    # Get original image bytes
+    original_png = await get_session_image(session_id, "original")
+    if not original_png:
+        raise HTTPException(status_code=400, detail="No original image found")
+
+    # Build context from vocab entries for richer descriptions
+    word_result = session.get("word_result") or {}
+    entries = word_result.get("vocab_entries") or word_result.get("entries") or []
+    vocab_context = ""
+    if entries:
+        sample = entries[:10]
+        words = [f"{e.get('english', '')} / {e.get('german', '')}" for e in sample if e.get('english')]
+        if words:
+            vocab_context = f"\nContext: This is a vocabulary page with words like: {', '.join(words)}"
+
+    ollama_base = os.getenv("OLLAMA_BASE_URL", "http://host.docker.internal:11434")
+    model = os.getenv("OLLAMA_HTR_MODEL", "qwen2.5vl:32b")
+
+    prompt = (
+        "Analyze this scanned page. Find ALL illustration/image/picture regions "
+        "(NOT text, NOT table cells, NOT blank areas). "
+        "For each image region found, return its bounding box as percentage of page dimensions "
+        "and a short English description of what the image shows. "
+        "Reply with ONLY a JSON array like: "
+        '[{"x": 10, "y": 20, "w": 30, "h": 25, "description": "drawing of a cat"}] '
+        "where x, y, w, h are percentages (0-100) of the page width/height. "
+        "If there are NO images on the page, return an empty array: []"
+        f"{vocab_context}"
+    )
+
+    img_b64 = base64.b64encode(original_png).decode("utf-8")
+    payload = {
+        "model": model,
+        "prompt": prompt,
+        "images": [img_b64],
+        "stream": False,
+    }
+
+    try:
+        async with httpx.AsyncClient(timeout=120.0) as client:
+            resp = await client.post(f"{ollama_base}/api/generate", json=payload)
+            resp.raise_for_status()
+            text = resp.json().get("response", "")
+
+        # Parse JSON array from response
+        match = re.search(r'\[.*?\]', text, re.DOTALL)
+        if match:
+            raw_regions = json.loads(match.group(0))
+        else:
+            raw_regions = []
+
+        # Normalize to ImageRegion format
+        regions = []
+        for r in raw_regions:
+            regions.append({
+                "bbox_pct": {
+                    "x": max(0, min(100, float(r.get("x", 0)))),
+                    "y": max(0, min(100, float(r.get("y", 0)))),
+                    "w": max(1, min(100, float(r.get("w", 10)))),
+                    "h": max(1, min(100, float(r.get("h", 10)))),
+                },
+                "description": r.get("description", ""),
+                "prompt": r.get("description", ""),
+                "image_b64": None,
+                "style": "educational",
+            })
+
+        # Enrich prompts with nearby vocab context
+        if entries:
+            for region in regions:
+                ry = region["bbox_pct"]["y"]
+                rh = region["bbox_pct"]["h"]
+                nearby = [
+                    e for e in entries
+                    if e.get("bbox") and abs(e["bbox"].get("y", 0) - ry) < rh + 10
+                ]
+                if nearby:
+                    en_words = [e.get("english", "") for e in nearby if e.get("english")]
+                    de_words = [e.get("german", "") for e in nearby if e.get("german")]
+                    if en_words or de_words:
+                        context = f" (vocabulary context: {', '.join(en_words[:5])}"
+                        if de_words:
+                            context += f" / {', '.join(de_words[:5])}"
+                        context += ")"
+                        region["prompt"] = region["description"] + context
+
+        # Save to ground_truth JSONB
+        ground_truth = session.get("ground_truth") or {}
+        validation = ground_truth.get("validation") or {}
+        validation["image_regions"] = regions
+        validation["detected_at"] = datetime.utcnow().isoformat()
+        ground_truth["validation"] = validation
+        await update_session_db(session_id, ground_truth=ground_truth)
+
+        if session_id in _cache:
+            _cache[session_id]["ground_truth"] = ground_truth
+
+        logger.info(f"Detected {len(regions)} image regions for session {session_id}")
+
+        return {"regions": regions, "count": len(regions)}
+
+    except httpx.ConnectError:
+        logger.warning(f"VLM not available at {ollama_base} for image detection")
+        return {"regions": [], "count": 0, "error": "VLM not available"}
+    except Exception as e:
+        logger.error(f"Image detection failed for {session_id}: {e}")
+        return {"regions": [], "count": 0, "error": str(e)}
+
+
+@router.post("/sessions/{session_id}/reconstruction/generate-image")
+async def generate_image_for_region(session_id: str, req: GenerateImageRequest):
+    """Generate a replacement image for a detected region using mflux.
+
+    Sends the prompt (with style suffix) to the mflux-service running
+    natively on the Mac Mini (Metal GPU required).
+    """
+    import httpx
+
+    session = await get_session_db(session_id)
+    if not session:
+        raise HTTPException(status_code=404, detail=f"Session {session_id} not found")
+
+    ground_truth = session.get("ground_truth") or {}
+    validation = ground_truth.get("validation") or {}
+    regions = validation.get("image_regions") or []
+
+    if req.region_index < 0 or req.region_index >= len(regions):
+        raise HTTPException(status_code=400, detail=f"Invalid region_index {req.region_index}, have {len(regions)} regions")
+
+    mflux_url = os.getenv("MFLUX_URL", "http://host.docker.internal:8095")
+    style_suffix = STYLE_SUFFIXES.get(req.style, STYLE_SUFFIXES["educational"])
+    full_prompt = f"{req.prompt}, {style_suffix}"
+
+    # Determine image size from region aspect ratio (snap to multiples of 64)
+    region = regions[req.region_index]
+    bbox = region["bbox_pct"]
+    aspect = bbox["w"] / max(bbox["h"], 1)
+    if aspect > 1.3:
+        width, height = 768, 512
+    elif aspect < 0.7:
+        width, height = 512, 768
+    else:
+        width, height = 512, 512
+
+    try:
+        async with httpx.AsyncClient(timeout=300.0) as client:
+            resp = await client.post(f"{mflux_url}/generate", json={
+                "prompt": full_prompt,
+                "width": width,
+                "height": height,
+                "steps": 4,
+            })
+            resp.raise_for_status()
+            data = resp.json()
+            image_b64 = data.get("image_b64")
+
+        if not image_b64:
+            return {"image_b64": None, "success": False, "error": "No image returned"}
+
+        # Save to ground_truth
+        regions[req.region_index]["image_b64"] = image_b64
+        regions[req.region_index]["prompt"] = req.prompt
+        regions[req.region_index]["style"] = req.style
+        validation["image_regions"] = regions
+        ground_truth["validation"] = validation
+        await update_session_db(session_id, ground_truth=ground_truth)
+
+        if session_id in _cache:
+            _cache[session_id]["ground_truth"] = ground_truth
+
+        logger.info(f"Generated image for session {session_id} region {req.region_index}")
+        return {"image_b64": image_b64, "success": True}
+
+    except httpx.ConnectError:
+        logger.warning(f"mflux-service not available at {mflux_url}")
+        return {"image_b64": None, "success": False, "error": f"mflux-service not available at {mflux_url}"}
+    except Exception as e:
+        logger.error(f"Image generation failed for {session_id}: {e}")
+        return {"image_b64": None, "success": False, "error": str(e)}
+
+
+@router.post("/sessions/{session_id}/reconstruction/validate")
+async def save_validation(session_id: str, req: ValidationRequest):
+    """Save final validation results for step 8.
+
+    Stores notes, score, and preserves any detected/generated image regions.
+    Sets current_step = 8 to mark pipeline as complete.
+    """
+    session = await get_session_db(session_id)
+    if not session:
+        raise HTTPException(status_code=404, detail=f"Session {session_id} not found")
+
+    ground_truth = session.get("ground_truth") or {}
+    validation = ground_truth.get("validation") or {}
+    validation["validated_at"] = datetime.utcnow().isoformat()
+    validation["notes"] = req.notes
+    validation["score"] = req.score
+    ground_truth["validation"] = validation
+
+    await update_session_db(session_id, ground_truth=ground_truth, current_step=8)
+
+    if session_id in _cache:
+        _cache[session_id]["ground_truth"] = ground_truth
+
+    logger.info(f"Validation saved for session {session_id}: score={req.score}")
+
+    return {"session_id": session_id, "validation": validation}
+
+
+@router.get("/sessions/{session_id}/reconstruction/validation")
+async def get_validation(session_id: str):
+    """Retrieve saved validation data for step 8."""
+    session = await get_session_db(session_id)
+    if not session:
+        raise HTTPException(status_code=404, detail=f"Session {session_id} not found")
+
+    ground_truth = session.get("ground_truth") or {}
+    validation = ground_truth.get("validation")
+
+    return {
+        "session_id": session_id,
+        "validation": validation,
+        "word_result": session.get("word_result"),
+    }
+
+
 @router.post("/sessions/{session_id}/reprocess")
 async def reprocess_session(session_id: str, request: Request):
     """Re-run pipeline from a specific step, clearing downstream data.

scripts/mflux-service.py

@@ -0,0 +1,121 @@
+#!/usr/bin/env python3
+"""
+mflux-service — Standalone FastAPI wrapper for mflux image generation.
+
+Runs NATIVELY on Mac Mini (requires Metal GPU, not Docker).
+Generates images using Flux Schnell via the mflux library.
+
+Setup:
+    python3 -m venv ~/mflux-env
+    source ~/mflux-env/bin/activate
+    pip install mflux fastapi uvicorn
+
+Run:
+    source ~/mflux-env/bin/activate
+    python scripts/mflux-service.py
+
+Or as a background service:
+    nohup ~/mflux-env/bin/python scripts/mflux-service.py > /tmp/mflux-service.log 2>&1 &
+
+License: Apache-2.0
+"""
+
+import base64
+import io
+import logging
+import os
+import time
+from typing import Optional
+
+import uvicorn
+from fastapi import FastAPI
+from pydantic import BaseModel
+
+logging.basicConfig(level=logging.INFO, format="%(asctime)s %(levelname)s %(message)s")
+logger = logging.getLogger("mflux-service")
+
+app = FastAPI(title="mflux Image Generation Service", version="1.0.0")
+
+# Lazy-loaded generator
+_flux = None
+
+
+def _get_flux():
+    """Lazy-load the Flux model on first use."""
+    global _flux
+    if _flux is None:
+        logger.info("Loading Flux Schnell model (first call, may download ~12 GB)...")
+        from mflux import Flux1
+
+        _flux = Flux1(
+            model_name="schnell",
+            quantize=8,
+        )
+        logger.info("Flux Schnell model loaded.")
+    return _flux
+
+
+class GenerateRequest(BaseModel):
+    prompt: str
+    width: int = 512
+    height: int = 512
+    steps: int = 4
+    seed: Optional[int] = None
+
+
+class GenerateResponse(BaseModel):
+    image_b64: Optional[str] = None
+    success: bool = True
+    error: Optional[str] = None
+    duration_ms: int = 0
+
+
+@app.get("/health")
+async def health():
+    return {"status": "ok", "model": "flux-schnell", "gpu": "metal"}
+
+
+@app.post("/generate", response_model=GenerateResponse)
+async def generate_image(req: GenerateRequest):
+    """Generate an image from a text prompt using Flux Schnell."""
+    t0 = time.time()
+
+    # Validate dimensions (must be multiples of 64 for Flux)
+    width = max(256, min(1024, (req.width // 64) * 64))
+    height = max(256, min(1024, (req.height // 64) * 64))
+
+    try:
+        from mflux import Config
+
+        flux = _get_flux()
+        image = flux.generate_image(
+            seed=req.seed or int(time.time()) % 2**31,
+            prompt=req.prompt,
+            config=Config(
+                num_inference_steps=req.steps,
+                height=height,
+                width=width,
+            ),
+        )
+
+        # Convert PIL image to base64
+        buf = io.BytesIO()
+        image.save(buf, format="PNG")
+        buf.seek(0)
+        img_b64 = "data:image/png;base64," + base64.b64encode(buf.read()).decode("utf-8")
+
+        duration_ms = int((time.time() - t0) * 1000)
+        logger.info(f"Generated {width}x{height} image in {duration_ms}ms: {req.prompt[:60]}...")
+
+        return GenerateResponse(image_b64=img_b64, success=True, duration_ms=duration_ms)
+
+    except Exception as e:
+        duration_ms = int((time.time() - t0) * 1000)
+        logger.error(f"Generation failed: {e}")
+        return GenerateResponse(image_b64=None, success=False, error=str(e), duration_ms=duration_ms)
+
+
+if __name__ == "__main__":
+    port = int(os.getenv("MFLUX_PORT", "8095"))
+    logger.info(f"Starting mflux-service on port {port}")
+    uvicorn.run(app, host="0.0.0.0", port=port)