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>

backend/frontend/static/manifest.json

@@ -0,0 +1,124 @@
+{
+  "name": "BreakPilot - Digitaler Lehrerassistent",
+  "short_name": "BreakPilot",
+  "description": "DSGVO-konforme KI-Unterstuetzung fuer Lehrkraefte",
+  "start_url": "/app",
+  "display": "standalone",
+  "background_color": "#0a0a0a",
+  "theme_color": "#6366f1",
+  "orientation": "any",
+  "scope": "/",
+  "lang": "de",
+  "categories": ["education", "productivity"],
+  "icons": [
+    {
+      "src": "/static/icons/icon-72.png",
+      "sizes": "72x72",
+      "type": "image/png",
+      "purpose": "any maskable"
+    },
+    {
+      "src": "/static/icons/icon-96.png",
+      "sizes": "96x96",
+      "type": "image/png",
+      "purpose": "any maskable"
+    },
+    {
+      "src": "/static/icons/icon-128.png",
+      "sizes": "128x128",
+      "type": "image/png",
+      "purpose": "any maskable"
+    },
+    {
+      "src": "/static/icons/icon-144.png",
+      "sizes": "144x144",
+      "type": "image/png",
+      "purpose": "any maskable"
+    },
+    {
+      "src": "/static/icons/icon-152.png",
+      "sizes": "152x152",
+      "type": "image/png",
+      "purpose": "any maskable"
+    },
+    {
+      "src": "/static/icons/icon-192.png",
+      "sizes": "192x192",
+      "type": "image/png",
+      "purpose": "any maskable"
+    },
+    {
+      "src": "/static/icons/icon-384.png",
+      "sizes": "384x384",
+      "type": "image/png",
+      "purpose": "any maskable"
+    },
+    {
+      "src": "/static/icons/icon-512.png",
+      "sizes": "512x512",
+      "type": "image/png",
+      "purpose": "any maskable"
+    }
+  ],
+  "screenshots": [
+    {
+      "src": "/static/screenshots/dashboard.png",
+      "sizes": "1280x720",
+      "type": "image/png",
+      "form_factor": "wide",
+      "label": "Dashboard mit Moduluebersicht"
+    },
+    {
+      "src": "/static/screenshots/klausur.png",
+      "sizes": "1280x720",
+      "type": "image/png",
+      "form_factor": "wide",
+      "label": "KI-gestuetzte Klausurkorrektur"
+    }
+  ],
+  "shortcuts": [
+    {
+      "name": "Neue Korrektur",
+      "short_name": "Korrektur",
+      "description": "Starte eine neue Klausurkorrektur",
+      "url": "/app?module=klausur-korrektur",
+      "icons": [{ "src": "/static/icons/shortcut-correction.png", "sizes": "96x96" }]
+    },
+    {
+      "name": "Unterricht starten",
+      "short_name": "Unterricht",
+      "description": "Starte den Unterrichtsbegleiter",
+      "url": "/app?module=companion",
+      "icons": [{ "src": "/static/icons/shortcut-lesson.png", "sizes": "96x96" }]
+    }
+  ],
+  "share_target": {
+    "action": "/app/share",
+    "method": "POST",
+    "enctype": "multipart/form-data",
+    "params": {
+      "title": "title",
+      "text": "text",
+      "url": "url",
+      "files": [
+        {
+          "name": "files",
+          "accept": ["image/*", "application/pdf"]
+        }
+      ]
+    }
+  },
+  "file_handlers": [
+    {
+      "action": "/app/open",
+      "accept": {
+        "application/pdf": [".pdf"],
+        "image/*": [".png", ".jpg", ".jpeg"]
+      }
+    }
+  ],
+  "handle_links": "preferred",
+  "launch_handler": {
+    "client_mode": "navigate-existing"
+  }
+}