fix(ocr-pipeline): show sub-columns in reconstruction and LLM review steps

- Add marker/bbox_marker fields to WordEntry type
- Add page_ref/column_marker colors to StepReconstruction
- Make StepLlmReview table dynamic based on columns_used metadata,
  showing all detected columns (EN, DE, Example, page_ref, marker)
  instead of hardcoded EN/DE/Beispiel only

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

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

@@ -264,6 +264,8 @@ export function StepReconstruction({ sessionId, onNext }: StepReconstructionProp
       column_de: 'border-green-400/40 focus:border-green-500',
       column_example: 'border-orange-400/40 focus:border-orange-500',
       column_text: 'border-purple-400/40 focus:border-purple-500',
+      page_ref: 'border-cyan-400/40 focus:border-cyan-500',
+      column_marker: 'border-gray-400/40 focus:border-gray-500',
     }
     return colors[colType] || 'border-gray-400/40 focus:border-gray-500'
   }