Ruff reports three safety findings in src/ui/pyqt/task_list.py: two B008 function-call defaults involving QModelIndex and one RUF012 mutable class attribute.
The implementation must respect Qt model override signatures and behavior. Use a safe shared invalid index or another Qt-compatible approach for defaults, and annotate or restructure the class-level role mapping so its ownership is explicit.
Acceptance criteria:
- Both B008 findings and the RUF012 finding are resolved.
- Qt model method signatures remain compatible.
- Task list model tests pass, including index and role behavior.
- No global Ruff rule is disabled.
Ruff reports three safety findings in src/ui/pyqt/task_list.py: two B008 function-call defaults involving QModelIndex and one RUF012 mutable class attribute.
The implementation must respect Qt model override signatures and behavior. Use a safe shared invalid index or another Qt-compatible approach for defaults, and annotate or restructure the class-level role mapping so its ownership is explicit.
Acceptance criteria: