feat(ocr-pipeline): ground-truth comparison tool for column detection

Side-by-side view: auto result (readonly) vs GT editor where teacher
draws correct columns. Diff table shows Auto vs GT with IoU matching.
GT data persisted per session for algorithm tuning.

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

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

@@ -47,6 +47,10 @@ interface ManualColumnEditorProps {
   onApply: (columns: PageRegion[]) => void
   onCancel: () => void
   applying: boolean
+  mode?: 'manual' | 'ground-truth'
+  layout?: 'two-column' | 'stacked'
+  initialDividers?: number[]
+  initialColumnTypes?: ColumnTypeKey[]
 }
 
 export function ManualColumnEditor({
@@ -56,13 +60,19 @@ export function ManualColumnEditor({
   onApply,
   onCancel,
   applying,
+  mode = 'manual',
+  layout = 'two-column',
+  initialDividers,
+  initialColumnTypes,
 }: ManualColumnEditorProps) {
   const containerRef = useRef<HTMLDivElement>(null)
-  const [dividers, setDividers] = useState<number[]>([]) // xPercent values
-  const [columnTypes, setColumnTypes] = useState<ColumnTypeKey[]>([])
+  const [dividers, setDividers] = useState<number[]>(initialDividers ?? [])
+  const [columnTypes, setColumnTypes] = useState<ColumnTypeKey[]>(initialColumnTypes ?? [])
   const [dragging, setDragging] = useState<number | null>(null)
   const [imageLoaded, setImageLoaded] = useState(false)
 
+  const isGT = mode === 'ground-truth'
+
   // Sync columnTypes length when dividers change
   useEffect(() => {
     const numColumns = dividers.length + 1
@@ -187,8 +197,8 @@ export function ManualColumnEditor({
 
   return (
     <div className="space-y-4">
-      {/* Two-column layout: image (left) + controls (right) */}
-      <div className="grid grid-cols-2 gap-4">
+      {/* Layout: image + controls */}
+      <div className={layout === 'stacked' ? 'space-y-4' : 'grid grid-cols-2 gap-4'}>
         {/* Left: Interactive image */}
         <div>
           <div className="flex items-center justify-between mb-1">
@@ -328,7 +338,11 @@ export function ManualColumnEditor({
               disabled={dividers.length === 0 || applying}
               className="w-full px-4 py-2 bg-teal-600 text-white rounded-lg hover:bg-teal-700 transition-colors text-sm font-medium disabled:opacity-50 disabled:cursor-not-allowed"
             >
-              {applying ? 'Wird gespeichert...' : `${dividers.length + 1} Spalten uebernehmen`}
+              {applying
+                ? 'Wird gespeichert...'
+                : isGT
+                  ? `${dividers.length + 1} Spalten als Ground Truth speichern`
+                  : `${dividers.length + 1} Spalten uebernehmen`}
             </button>
             <button
               onClick={() => setDividers([])}