feat: A/B Testing + Compliance Report PDF (F5 + F8)

F5: A/B Testing for Consent Rate
- Migration 116: banner_variants table + variant tracking in audit log
- BannerABService: deterministic sticky bucketing via device hash,
  chi-squared significance testing, variant CRUD
- banner_ab_routes: 6 endpoints (CRUD + stats + assign)
- ABTestPanel.tsx: variant creation, traffic sliders, opt-in comparison
  chart with winner/significance badges
- New "A/B-Test" tab in cookie-banner page

F8: Compliance Report PDF
- CompliancePDFGenerator: reportlab-based A4 PDF covering all modules
  (Company Profile, TOM, VVT, DSFA, Risks, Vendors, Incidents,
  Reviews, Consents, Roles)
- compliance_report_routes: GET /compliance/report/pdf
- "Compliance-Report herunterladen" button on SDK dashboard

[migration-approved]

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

backend-compliance/compliance/api/__init__.py

@@ -66,6 +66,8 @@ _ROUTER_MODULES = [
     "org_role_routes",
     "document_review_routes",
     "banner_analytics_routes",
+    "banner_ab_routes",
+    "compliance_report_routes",
 ]
 
 _loaded_count = 0