feat(quaidal): backend API + frontend tab for BSI QUAIDAL data-quality controls

Wire the 195 Clean-Room QUAIDAL controls (from breakpilot-core migration 011)
into the compliance SaaS UI.

Backend:
- GET /api/v1/quaidal/stats           - counts by kind + source provenance
- GET /api/v1/quaidal/controls        - list, optional kind= filter
- GET /api/v1/quaidal/controls/{id}   - single derived control
- GET /api/v1/quaidal/criteria        - 10 QKB criteria
- GET /api/v1/quaidal/criteria/{id}   - QKB with QB/MA/QM tree

Frontend:
- /sdk/quality: new "Trainingsdaten-Qualität (BSI QUAIDAL)" tab with
  10 QKB cards and a drill-down modal showing the full QB→MA→QM tree
  plus original BSI source link and license note.
- /sdk/ai-act: Art. 10 tile on each high-risk/unacceptable result,
  linking to /sdk/quality?category=data_quality.

Pattern matches existing IACE module DIN-reference handling:
own wording, source section + URL preserved for due diligence.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

backend-compliance/main.py

@@ -55,6 +55,7 @@ from compliance.api.saving_scan_routes import router as saving_scan_router
 from compliance.api.agent_migration_routes import router as agent_migration_router
 from compliance.api.vendor_assessment_routes import router as vendor_assessment_router
 from compliance.api.cra_routes import router as cra_router
+from compliance.api.quaidal_routes import router as quaidal_router
 
 # Middleware
 from middleware import (
@@ -168,6 +169,7 @@ app.include_router(vendor_assessment_router, prefix="/api")
 
 # CRA (Cyber Resilience Act) Compliance
 app.include_router(cra_router, prefix="/api")
+app.include_router(quaidal_router, prefix="/api")
 
 
 if __name__ == "__main__":