feat: add Woerterbuch category + column add/delete in grid editor

- New document category "Woerterbuch" (frontend type + backend validation)
- Column delete: hover column header → red "x" button (with confirmation)
- Column add: hover column header → "+" button inserts after that column
- Both operations support undo/redo, update cell IDs and summary
- Available in both GridEditor and StepGridReview (Kombi last step)

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

admin-lehrer/components/grid-editor/useGridEditor.ts

@@ -212,6 +212,131 @@ export function useGridEditor(sessionId: string | null) {
     [grid, pushUndo],
   )
 
+  // ------------------------------------------------------------------
+  // Column management
+  // ------------------------------------------------------------------
+
+  const deleteColumn = useCallback(
+    (zoneIndex: number, colIndex: number) => {
+      if (!grid) return
+      const zone = grid.zones.find((z) => z.zone_index === zoneIndex)
+      if (!zone || zone.columns.length <= 1) return // keep at least 1 column
+      pushUndo(grid.zones)
+
+      setGrid((prev) => {
+        if (!prev) return prev
+        return {
+          ...prev,
+          zones: prev.zones.map((z) => {
+            if (z.zone_index !== zoneIndex) return z
+            const newColumns = z.columns
+              .filter((c) => c.index !== colIndex)
+              .map((c, i) => ({ ...c, index: i, label: `column_${i + 1}` }))
+            const newCells = z.cells
+              .filter((c) => c.col_index !== colIndex)
+              .map((c) => {
+                const newCI = c.col_index > colIndex ? c.col_index - 1 : c.col_index
+                return {
+                  ...c,
+                  col_index: newCI,
+                  cell_id: `Z${zoneIndex}_R${String(c.row_index).padStart(2, '0')}_C${newCI}`,
+                }
+              })
+            return { ...z, columns: newColumns, cells: newCells }
+          }),
+          summary: {
+            ...prev.summary,
+            total_columns: prev.summary.total_columns - 1,
+            total_cells: prev.zones.reduce(
+              (sum, z) =>
+                sum +
+                (z.zone_index === zoneIndex
+                  ? z.cells.filter((c) => c.col_index !== colIndex).length
+                  : z.cells.length),
+              0,
+            ),
+          },
+        }
+      })
+      setDirty(true)
+    },
+    [grid, pushUndo],
+  )
+
+  const addColumn = useCallback(
+    (zoneIndex: number, afterColIndex: number) => {
+      if (!grid) return
+      const zone = grid.zones.find((z) => z.zone_index === zoneIndex)
+      if (!zone) return
+      pushUndo(grid.zones)
+
+      const newColIndex = afterColIndex + 1
+
+      setGrid((prev) => {
+        if (!prev) return prev
+        return {
+          ...prev,
+          zones: prev.zones.map((z) => {
+            if (z.zone_index !== zoneIndex) return z
+            // Shift existing columns
+            const shiftedCols = z.columns.map((c) =>
+              c.index > afterColIndex ? { ...c, index: c.index + 1, label: `column_${c.index + 2}` } : c,
+            )
+            // Insert new column
+            const refCol = z.columns.find((c) => c.index === afterColIndex) || z.columns[z.columns.length - 1]
+            const newCol = {
+              index: newColIndex,
+              label: `column_${newColIndex + 1}`,
+              x_min_px: refCol.x_max_px,
+              x_max_px: refCol.x_max_px + (refCol.x_max_px - refCol.x_min_px),
+              x_min_pct: refCol.x_max_pct,
+              x_max_pct: Math.min(100, refCol.x_max_pct + (refCol.x_max_pct - refCol.x_min_pct)),
+              bold: false,
+            }
+            const allCols = [...shiftedCols, newCol].sort((a, b) => a.index - b.index)
+
+            // Shift existing cells and create empty cells for new column
+            const shiftedCells = z.cells.map((c) => {
+              if (c.col_index > afterColIndex) {
+                const newCI = c.col_index + 1
+                return {
+                  ...c,
+                  col_index: newCI,
+                  cell_id: `Z${zoneIndex}_R${String(c.row_index).padStart(2, '0')}_C${newCI}`,
+                }
+              }
+              return c
+            })
+            // Create empty cells for each row
+            const newCells = z.rows.map((row) => ({
+              cell_id: `Z${zoneIndex}_R${String(row.index).padStart(2, '0')}_C${newColIndex}`,
+              zone_index: zoneIndex,
+              row_index: row.index,
+              col_index: newColIndex,
+              col_type: `column_${newColIndex + 1}`,
+              text: '',
+              confidence: 0,
+              bbox_px: { x: 0, y: 0, w: 0, h: 0 },
+              bbox_pct: { x: 0, y: 0, w: 0, h: 0 },
+              word_boxes: [],
+              ocr_engine: 'manual',
+              is_bold: false,
+            }))
+
+            return { ...z, columns: allCols, cells: [...shiftedCells, ...newCells] }
+          }),
+          summary: {
+            ...prev.summary,
+            total_columns: prev.summary.total_columns + 1,
+            total_cells: prev.summary.total_cells + (zone?.rows.length ?? 0),
+          },
+        }
+      })
+      setDirty(true)
+    },
+    [grid, pushUndo],
+  )
+
   // ------------------------------------------------------------------
   // Undo / Redo
   // ------------------------------------------------------------------
@@ -284,5 +409,7 @@ export function useGridEditor(sessionId: string | null) {
     canUndo,
     canRedo,
     getAdjacentCell,
+    deleteColumn,
+    addColumn,
   }
 }