fix(routers+imports): fix missing DetectionRule import and correct -> list return type annotations that actually return paginated dicts

backend/app/routers/detection_rules.py

@@ -80,7 +80,7 @@ def list_detection_rules(
     db: Session = Depends(get_db),
     # Entry: current_user
     current_user: User = Depends(get_current_user),
-) -> list:
+) -> dict:
     """List detection rules with optional filters and pagination."""
     # Return list_rules(
     return list_rules(
@@ -112,7 +112,7 @@ def get_detection_rules_for_template(
     db: Session = Depends(get_db),
     # Entry: current_user
     current_user: User = Depends(get_current_user),
-) -> list:
+) -> dict:
     """Get detection rules associated with a test template."""
     # Return get_rules_for_template(db, template_id)
     return get_rules_for_template(db, template_id)
@@ -151,7 +151,7 @@ def get_detection_rules_for_test(
     db: Session = Depends(get_db),
     # Entry: current_user
     current_user: User = Depends(get_current_user),
-) -> list:
+) -> dict:
     """Get detection rules relevant to a test, along with their evaluation results.
 
     Finds rules by matching the test's technique_id to detection rules,