fix: resolve test failures and lint errors after segment 5 merge

- Add login_manager mock to controller test fixtures (6 files)
- Remove duplicate MemoryConfig import in llm_utils.py
- Fix line-too-long in test_workflow_draft_variable.py

Made-with: Cursor

api/tests/unit_tests/core/app/workflow/layers/test_persistence.py

@@ -42,6 +42,7 @@ def test_update_node_execution_prefers_event_finished_at(monkeypatch: pytest.Mon
         predecessor_node_id=None,
         iteration_id="iter-1",
         loop_id=None,
+        parent_node_id=None,
         created_at=node_execution.created_at,
     )