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/api/tests/registry/discovery/__init__.py

@@ -0,0 +1,16 @@
+"""
+Test Discovery Module
+
+Functions for discovering tests in various frameworks.
+"""
+
+from .go_discovery import discover_go_tests
+from .python_discovery import discover_python_tests, discover_bqas_tests
+from .service_builder import build_service_info
+
+__all__ = [
+    "discover_go_tests",
+    "discover_python_tests",
+    "discover_bqas_tests",
+    "build_service_info",
+]