Remove A/B testing toggles from studio-v2 (customer frontend)

Dev-only toggles belong in admin-lehrer (port 3002) only.
The customer frontend runs the pipeline with optimal defaults
and shows only the finished results.

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

studio-v2/app/vocab-worksheet/components/VocabularyTab.tsx

@@ -120,36 +120,6 @@ export function VocabularyTab({ h }: { h: VocabWorksheetHook }) {
           </div>
         </div>
 
-        {/* OCR Quality Steps (A/B Testing) */}
-        <div className={`flex items-center gap-3 mb-3 flex-shrink-0 flex-wrap ${isDark ? 'text-white/60' : 'text-slate-500'}`}>
-          <span className="text-xs font-medium">Steps:</span>
-          <label className="flex items-center gap-1 text-xs cursor-pointer">
-            <input type="checkbox" checked={h.ocrEnhance} onChange={(e) => h.setOcrEnhance(e.target.checked)} className="rounded" />
-            CLAHE
-          </label>
-          <label className="flex items-center gap-1 text-xs">
-            <span>MaxCols:</span>
-            <select value={h.ocrMaxCols} onChange={(e) => h.setOcrMaxCols(Number(e.target.value))} className={`px-1 py-0.5 text-xs rounded border ${isDark ? 'border-white/20 bg-white/10 text-white' : 'border-gray-200 bg-white text-gray-600'}`}>
-              <option value={0}>unbegrenzt</option>
-              <option value={2}>2</option>
-              <option value={3}>3</option>
-              <option value={4}>4</option>
-              <option value={5}>5</option>
-            </select>
-          </label>
-          <label className="flex items-center gap-1 text-xs">
-            <span>MinConf:</span>
-            <select value={h.ocrMinConf} onChange={(e) => h.setOcrMinConf(Number(e.target.value))} className={`px-1 py-0.5 text-xs rounded border ${isDark ? 'border-white/20 bg-white/10 text-white' : 'border-gray-200 bg-white text-gray-600'}`}>
-              <option value={0}>auto</option>
-              <option value={20}>20</option>
-              <option value={30}>30</option>
-              <option value={40}>40</option>
-              <option value={50}>50</option>
-              <option value={60}>60</option>
-            </select>
-          </label>
-        </div>
-
         {/* Error messages for failed pages */}
         {h.processingErrors.length > 0 && (
           <div className={`rounded-xl p-3 mb-3 flex-shrink-0 ${isDark ? 'bg-orange-500/20 text-orange-200 border border-orange-500/30' : 'bg-orange-100 text-orange-700 border border-orange-200'}`}>

studio-v2/app/vocab-worksheet/types.ts

@@ -140,13 +140,6 @@ export interface VocabWorksheetHook {
   showSettings: boolean
   setShowSettings: (show: boolean) => void
 
-  // OCR Quality Steps (A/B testing)
-  ocrEnhance: boolean
-  setOcrEnhance: (v: boolean) => void
-  ocrMaxCols: number
-  setOcrMaxCols: (v: number) => void
-  ocrMinConf: number
-  setOcrMinConf: (v: number) => void
 
   // QR
   showQRModal: boolean

studio-v2/app/vocab-worksheet/useVocabWorksheet.ts

@@ -868,7 +868,6 @@ export function useVocabWorksheet(): VocabWorksheetHook {
     processingErrors, successfulPages, failedPages, currentlyProcessingPage,
     // OCR settings
     ocrPrompts, showSettings, setShowSettings,
-    ocrEnhance, setOcrEnhance, ocrMaxCols, setOcrMaxCols, ocrMinConf, setOcrMinConf,
     // QR
     showQRModal, setShowQRModal, uploadSessionId,
     mobileUploadedFiles, selectedMobileFile, setSelectedMobileFile, setMobileUploadedFiles,