fix: CV-gated syllable insertion + grid editor scroll

1. Syllable dividers now require CV validation: morphological vertical
   line detection checks if word_box image actually shows thin isolated
   pipe lines before applying pyphen. Only first word per cell gets
   pipes (matching dictionary print layout).

2. Grid editor scroll: changed maxHeight from 80vh to calc(100vh-200px)
   so editor remains scrollable after edits.

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

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

@@ -314,7 +314,7 @@ export function StepGridReview({ sessionId, onNext, saveRef }: StepGridReviewPro
         )}
 
         {/* Right: Grid with row-accept buttons */}
-        <div className="space-y-3 overflow-y-auto" style={{ maxHeight: '80vh' }}>
+        <div className="space-y-3 overflow-y-auto" style={{ maxHeight: 'calc(100vh - 200px)' }}>
 
           {/* Zone tables with row-accept buttons */}
           {(() => {