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/tests/test_integration/__init__.py

@@ -0,0 +1,16 @@
+"""
+Integration tests that require external services.
+
+These tests run in the Woodpecker CI integration pipeline
+(.woodpecker/integration.yml) which provides:
+- PostgreSQL database
+- Valkey/Redis cache
+
+To run locally:
+    docker compose -f docker-compose.test.yml up -d postgres-test valkey-test
+    export DATABASE_URL=postgresql://breakpilot:breakpilot_test@localhost:55432/breakpilot_test
+    export VALKEY_URL=redis://localhost:56379
+    export SKIP_INTEGRATION_TESTS=false
+    pytest tests/test_integration/ -v
+    docker compose -f docker-compose.test.yml down -v
+"""