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>

admin-v2/vitest.setup.ts

@@ -0,0 +1,48 @@
+import '@testing-library/jest-dom'
+import React from 'react'
+import { afterEach, vi } from 'vitest'
+import { cleanup } from '@testing-library/react'
+
+// Cleanup after each test
+afterEach(() => {
+  cleanup()
+})
+
+// Mock Next.js router
+vi.mock('next/navigation', () => ({
+  useRouter: () => ({
+    push: vi.fn(),
+    replace: vi.fn(),
+    prefetch: vi.fn(),
+    back: vi.fn(),
+    forward: vi.fn(),
+  }),
+  usePathname: () => '/sdk',
+  useSearchParams: () => new URLSearchParams(),
+}))
+
+// Mock Next.js Link component
+vi.mock('next/link', () => ({
+  default: ({ children, href, ...props }: { children: React.ReactNode; href: string; [key: string]: unknown }) => {
+    return React.createElement('a', { href: href || '#', ...props }, children)
+  },
+}))
+
+// Mock localStorage
+const localStorageMock = {
+  getItem: vi.fn(),
+  setItem: vi.fn(),
+  removeItem: vi.fn(),
+  clear: vi.fn(),
+}
+Object.defineProperty(window, 'localStorage', { value: localStorageMock })
+
+// Mock URL.createObjectURL and URL.revokeObjectURL for export tests
+Object.defineProperty(URL, 'createObjectURL', {
+  writable: true,
+  value: vi.fn(() => 'blob:mock-url'),
+})
+Object.defineProperty(URL, 'revokeObjectURL', {
+  writable: true,
+  value: vi.fn(),
+})