fix: Restore all files lost during destructive rebase

A previous `git pull --rebase origin main` dropped 177 local commits,
losing 3400+ files across admin-v2, backend, studio-v2, website,
klausur-service, and many other services. The partial restore attempt
(660295e2) only recovered some files.

This commit restores all missing files from pre-rebase ref 98933f5e
while preserving post-rebase additions (night-scheduler, night-mode UI,
NightModeWidget dashboard integration).

Restored features include:
- AI Module Sidebar (FAB), OCR Labeling, OCR Compare
- GPU Dashboard, RAG Pipeline, Magic Help
- Klausur-Korrektur (8 files), Abitur-Archiv (5+ files)
- Companion, Zeugnisse-Crawler, Screen Flow
- Full backend, studio-v2, website, klausur-service
- All compliance SDKs, agent-core, voice-service
- CI/CD configs, documentation, scripts

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

studio-v2/components/worksheet-editor/PageNavigator.tsx

@@ -0,0 +1,126 @@
+'use client'
+
+import { useTheme } from '@/lib/ThemeContext'
+import { useLanguage } from '@/lib/LanguageContext'
+import { useWorksheet } from '@/lib/worksheet-editor/WorksheetContext'
+
+interface PageNavigatorProps {
+  className?: string
+}
+
+export function PageNavigator({ className = '' }: PageNavigatorProps) {
+  const { isDark } = useTheme()
+  const { t } = useLanguage()
+  const {
+    document,
+    currentPageIndex,
+    setCurrentPageIndex,
+    addPage,
+    deletePage,
+    canvas
+  } = useWorksheet()
+
+  const pages = document?.pages || []
+
+  const handlePageChange = (index: number) => {
+    if (!canvas || !document || index === currentPageIndex) return
+
+    // Save current page state
+    const currentPage = document.pages[currentPageIndex]
+    if (currentPage) {
+      currentPage.canvasJSON = JSON.stringify(canvas.toJSON())
+    }
+
+    // Load new page
+    setCurrentPageIndex(index)
+    const newPage = document.pages[index]
+    if (newPage?.canvasJSON) {
+      canvas.loadFromJSON(JSON.parse(newPage.canvasJSON), () => {
+        canvas.renderAll()
+      })
+    } else {
+      // Clear canvas for new page
+      canvas.clear()
+      canvas.backgroundColor = '#ffffff'
+      canvas.renderAll()
+    }
+  }
+
+  // Glassmorphism styles
+  const containerStyle = isDark
+    ? 'backdrop-blur-xl bg-white/10 border border-white/20'
+    : 'backdrop-blur-xl bg-white/70 border border-black/10 shadow-xl'
+
+  const pageButtonStyle = (isActive: boolean) => isDark
+    ? isActive
+      ? 'bg-purple-500/30 text-purple-300 border-purple-400/50'
+      : 'bg-white/5 text-white/70 border-white/10 hover:bg-white/10'
+    : isActive
+      ? 'bg-purple-100 text-purple-700 border-purple-300'
+      : 'bg-white/50 text-slate-600 border-slate-200 hover:bg-slate-100'
+
+  const labelStyle = isDark ? 'text-white/70' : 'text-slate-600'
+
+  return (
+    <div className={`flex items-center gap-3 p-3 rounded-2xl ${containerStyle} ${className}`}>
+      {/* Page Label */}
+      <span className={`text-sm font-medium ${labelStyle}`}>
+        Seiten:
+      </span>
+
+      {/* Page Buttons */}
+      <div className="flex items-center gap-2">
+        {pages.map((page, index) => (
+          <div key={page.id} className="relative group">
+            <button
+              onClick={() => handlePageChange(index)}
+              className={`w-10 h-10 flex items-center justify-center rounded-lg border text-sm font-medium transition-all ${pageButtonStyle(index === currentPageIndex)}`}
+            >
+              {index + 1}
+            </button>
+
+            {/* Delete button (visible on hover, not for single page) */}
+            {pages.length > 1 && (
+              <button
+                onClick={(e) => {
+                  e.stopPropagation()
+                  deletePage(index)
+                }}
+                className={`absolute -top-2 -right-2 w-5 h-5 rounded-full flex items-center justify-center opacity-0 group-hover:opacity-100 transition-opacity ${
+                  isDark
+                    ? 'bg-red-500/80 text-white hover:bg-red-500'
+                    : 'bg-red-500 text-white hover:bg-red-600'
+                }`}
+                title="Seite löschen"
+              >
+                <svg className="w-3 h-3" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+                  <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M6 18L18 6M6 6l12 12" />
+                </svg>
+              </button>
+            )}
+          </div>
+        ))}
+
+        {/* Add Page Button */}
+        <button
+          onClick={addPage}
+          className={`w-10 h-10 flex items-center justify-center rounded-lg border border-dashed transition-all ${
+            isDark
+              ? 'border-white/30 text-white/50 hover:border-white/50 hover:text-white/70 hover:bg-white/5'
+              : 'border-slate-300 text-slate-400 hover:border-slate-400 hover:text-slate-500 hover:bg-slate-50'
+          }`}
+          title="Seite hinzufügen"
+        >
+          <svg className="w-5 h-5" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+            <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M12 4v16m8-8H4" />
+          </svg>
+        </button>
+      </div>
+
+      {/* Page Info */}
+      <span className={`text-sm ${labelStyle}`}>
+        {currentPageIndex + 1} / {pages.length}
+      </span>
+    </div>
+  )
+}