Add gutter repair step to OCR Kombi pipeline

New step "Wortkorrektur" between Grid-Review and Ground Truth that detects
and fixes words truncated or blurred at the book gutter (binding area) of
double-page scans. Uses pyspellchecker (DE+EN) for validation.

Two repair strategies:
- hyphen_join: words split across rows with missing chars (ve + künden → verkünden)
- spell_fix: garbled trailing chars from gutter blur (stammeli → stammeln)

Interactive frontend with per-suggestion accept/reject and batch controls.

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

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

@@ -15,6 +15,7 @@ import { StepOcr } from '@/components/ocr-kombi/StepOcr'
 import { StepStructure } from '@/components/ocr-kombi/StepStructure'
 import { StepGridBuild } from '@/components/ocr-kombi/StepGridBuild'
 import { StepGridReview } from '@/components/ocr-kombi/StepGridReview'
+import { StepGutterRepair } from '@/components/ocr-kombi/StepGutterRepair'
 import { StepGroundTruth } from '@/components/ocr-kombi/StepGroundTruth'
 import { useKombiPipeline } from './useKombiPipeline'
 
@@ -93,6 +94,8 @@ function OcrKombiContent() {
       case 9:
         return <StepGridReview sessionId={sessionId} onNext={handleNext} saveRef={gridSaveRef} />
       case 10:
+        return <StepGutterRepair sessionId={sessionId} onNext={handleNext} />
+      case 11:
         return (
           <StepGroundTruth
             sessionId={sessionId}