refactor(tests): extract CRUD/query logic to test_crud_service, router delegates to service with domain exceptions

backend/tests/test_templates_crud.py

@@ -101,7 +101,7 @@ from app.routers.test_templates import (
     toggle_template_active,
     template_stats,
 )
-from app.routers.tests import create_test_from_template
+from app.services.test_crud_service import create_test_from_template as crud_create_from_template
 from app.schemas.test_template import TestTemplateCreate
 
 
@@ -174,7 +174,8 @@ def test_get_templates_by_technique():
 
 def test_instantiate_template():
     """POST /tests/from-template creates a test pre-filled from template data."""
-    source = inspect.getsource(create_test_from_template)
+    # Template field copying lives in the service; router delegates to it
+    source = inspect.getsource(crud_create_from_template)
 
     # Verify it reads from template and copies fields
     assert "template" in source, "Must reference template"