- Introduced `StageUseTargetCaptureBar` class for managing user interactions with props and their use spots.
- Implemented UI elements including buttons for changing props and canceling actions.
- Added `PropUseSpotData` class for validation and serialization of prop use spots.
- Created tests for validating use spot data migration, serialization, and rule matching.
- Ensured proper handling of edge cases in use spot data, including unique IDs and finite positions.
