StepAnsicht: fix font size and row spacing to match original

- Font: use font_size_suggestion_px * scale directly (removed 0.85 factor)
- Row height: calculate from row-to-row spacing (y_min of next row
  minus y_min of current row) instead of text height (y_max - y_min).
  This produces correct line spacing matching the original layout.
- Multi-line cells: height multiplied by line count

Content zone should now span from ~250 to ~2050 matching the original.

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

admin-lehrer/components/ocr-kombi/StepAnsicht.tsx

@@ -71,7 +71,8 @@ export function StepAnsicht({ sessionId, onNext }: StepAnsichtProps) {
   const panelHeight = imgH * scale
 
   const baseFontPx = (grid as any).layout_metrics?.font_size_suggestion_px || 14
-  const scaledFont = Math.max(7, baseFontPx * scale * 0.85)
+  const avgRowH = (grid as any).layout_metrics?.avg_row_height_px || 31
+  const scaledFont = Math.max(7, baseFontPx * scale)
 
   // Collect all word boxes for OCR overlay
   const allWordBoxes = grid.zones.flatMap((z) =>
@@ -161,7 +162,7 @@ export function StepAnsicht({ sessionId, onNext }: StepAnsichtProps) {
 
           {/* Rendered zones */}
           {grid.zones.map((zone) => (
-            <ZoneRenderer key={zone.zone_index} zone={zone} scale={scale} fontSize={scaledFont} />
+            <ZoneRenderer key={zone.zone_index} zone={zone} scale={scale} fontSize={scaledFont} avgRowH={avgRowH} />
           ))}
 
           {/* Coordinate grid */}
@@ -208,8 +209,8 @@ function CoordinateGrid({ imgW, imgH, scale, spacing }: {
 // Zone renderer (reconstruction side)
 // ---------------------------------------------------------------------------
 
-function ZoneRenderer({ zone, scale, fontSize }: {
-  zone: GridZone; scale: number; fontSize: number
+function ZoneRenderer({ zone, scale, fontSize, avgRowH }: {
+  zone: GridZone; scale: number; fontSize: number; avgRowH: number
 }) {
   const isBox = zone.zone_type === 'box'
   const boxColor = (zone as any).box_bg_hex || '#6b7280'
@@ -253,10 +254,22 @@ function ZoneRenderer({ zone, scale, fontSize }: {
       }}
     >
       <div style={{ display: 'grid', gridTemplateColumns: scaledColWidths.map((w) => `${w.toFixed(1)}px`).join(' ') }}>
-        {zone.rows.map((row) => {
+        {zone.rows.map((row, rowIdx) => {
           const isSpanning = zone.cells.some((c) => c.row_index === row.index && c.col_type === 'spanning_header')
-          const measuredH = (row.y_max_px ?? 0) - (row.y_min_px ?? 0)
-          const rowH = Math.max(fontSize * 1.3, measuredH * scale)
+
+          // Row height = distance to next row's start (not text height)
+          // This produces correct line spacing matching the original
+          const nextRow = rowIdx + 1 < zone.rows.length ? zone.rows[rowIdx + 1] : null
+          const rowStartY = row.y_min_px ?? row.y_min ?? 0
+          const nextStartY = nextRow ? (nextRow.y_min_px ?? nextRow.y_min ?? 0) : rowStartY + avgRowH
+          const rowSpacing = nextStartY - rowStartY
+          const rowH = Math.max(fontSize * 1.3, rowSpacing * scale)
+
+          // Multi-line cells need more height
+          const maxLines = Math.max(1, ...zone.cells
+            .filter((c) => c.row_index === row.index)
+            .map((c) => (c.text ?? '').split('\n').length))
+          const effectiveRowH = rowH * Math.max(1, maxLines)
 
           return (
             <div key={row.index} style={{ display: 'contents' }}>
@@ -273,7 +286,7 @@ function ZoneRenderer({ zone, scale, fontSize }: {
                         className={`px-0.5 overflow-hidden ${row.is_header ? 'font-bold' : ''}`}
                         style={{
                           gridColumn: `${cell.col_index + 1} / ${cell.col_index + 1 + colspan}`,
-                          minHeight: `${rowH}px`,
+                          minHeight: `${effectiveRowH}px`,
                           color: color || undefined,
                           whiteSpace: 'pre-wrap',
                         }}