fix(lint): convert custom noqa directives to regular comments

Ruff only accepts standard rule codes (e.g., E712, F401) in noqa
directives. Custom architecture validator codes (SEC-034, SVC-006,
MOD-004, API-007) are now regular comments instead.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

middleware/auth.py

@@ -502,6 +502,6 @@ class AuthManager:
             db.refresh(admin_user)
 
             # Log creation for audit trail (credentials redacted for security)
-            logger.info("Default admin user created")  # noqa: sec-001 sec-021
+            logger.info("Default admin user created")  # sec-001 sec-021
 
         return admin_user