fix: correct tojson|safe usage in templates and update validator

- Remove |safe from |tojson in HTML attributes (x-data) - quotes must
  become " for browsers to parse correctly
- Update LANG-002 and LANG-003 architecture rules to document correct
  |tojson usage patterns:
  - HTML attributes: |tojson (no |safe)
  - Script blocks: |tojson|safe
- Fix validator to warn when |tojson|safe is used in x-data (breaks
  HTML attribute parsing)
- Improve code quality across services, APIs, and tests

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

app/api/v1/admin/__init__.py

@@ -151,9 +151,7 @@ router.include_router(
 )
 
 # Include test runner endpoints
-router.include_router(
-    tests.router, prefix="/tests", tags=["admin-tests"]
-)
+router.include_router(tests.router, prefix="/tests", tags=["admin-tests"])
 
 # Export the router
 __all__ = ["router"]