fix: remove AIToolsSidebarResponsive wrapper from ground-truth and regression pages

AIToolsSidebarResponsive does not accept children — it renders only a
sidebar nav. Using it as a wrapper caused page content to never render.
Replaced with plain div, matching the pattern used by ocr-pipeline.

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

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

@@ -15,7 +15,6 @@
 
 import { useState, useEffect, useCallback, useRef } from 'react'
 import { PagePurpose } from '@/components/common/PagePurpose'
-import { AIToolsSidebarResponsive } from '@/components/ai/AIToolsSidebar'
 
 const KLAUSUR_API = '/klausur-api'
 
@@ -271,7 +270,7 @@ export default function GroundTruthReviewPage() {
     : null
 
   return (
-    <AIToolsSidebarResponsive>
+    <div className="space-y-6">
       <div className="max-w-[1600px] mx-auto p-4 space-y-4">
         <PagePurpose
           title="Ground Truth Review"
@@ -588,6 +587,6 @@ export default function GroundTruthReviewPage() {
           </details>
         )}
       </div>
-    </AIToolsSidebarResponsive>
+    </div>
   )
 }

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

@@ -9,7 +9,6 @@
 
 import { useState, useEffect, useCallback } from 'react'
 import { PagePurpose } from '@/components/common/PagePurpose'
-import { AIToolsSidebarResponsive } from '@/components/ai/AIToolsSidebar'
 
 const KLAUSUR_API = '/klausur-api'
 
@@ -165,7 +164,7 @@ export default function OCRRegressionPage() {
   const totalError = results.filter(r => r.status === 'error').length
 
   return (
-    <AIToolsSidebarResponsive>
+    <div className="space-y-6">
       <div className="max-w-7xl mx-auto p-6 space-y-6">
         <PagePurpose
           title="OCR Regression Tests"
@@ -399,6 +398,6 @@ export default function OCRRegressionPage() {
           </div>
         )}
       </div>
-    </AIToolsSidebarResponsive>
+    </div>
   )
 }