fix: D3FEND expandable cards, System page cleanup, and multi-source improvements

- Make D3FEND defense cards clickable with expandable details and external link
- Fix D3FEND URLs to use PascalCase technique names matching the ontology
- Remove duplicate Import Atomic Red Team from System page (use Data Sources)
- Add bulk Activate All / Deactivate All buttons with confirmation modal
- Fix template admin list to show both active and inactive templates
- Add PATCH /test-templates/bulk-activate backend endpoint
- Auto-seed data sources on container startup via entrypoint.sh
- Fix SigmaHQ, CALDERA, GTFOBins import issues
- Register D3FEND sync handler in data sources router
- Add CIS Controls v8 compliance framework import
- Expand Test Catalog source filters (CALDERA, LOLBAS, GTFOBins)
- Campaign Generate from Threat Actor now opens actor selector modal
- Add coverage snapshot creation button to Comparison page
- Update README with accurate data source and feature documentation

backend/app/routers/data_sources.py

@@ -40,7 +40,7 @@ def _get_sync_handler(source_name: str):
         "caldera": ("app.services.caldera_import_service", "sync"),
         "elastic_rules": ("app.services.elastic_import_service", "sync"),
         "mitre_cti": ("app.services.threat_actor_import_service", "sync"),
-        # d3fend added in later phases
+        "d3fend": ("app.services.d3fend_import_service", "sync"),
     }
 
     if source_name not in handlers: