- 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.
- Added UI/UX specification for prop roles and set down mechanics in phase 17a.
- Created `PropStageRoles` script to manage normalized behavior for props, including depth, motion, and collision settings.
- Introduced `StagePhysicsPolicy` for shared physics configurations related to props and actors.
- Developed comprehensive tests for prop roles, including default settings, legacy migration, serialization, and runtime behavior.
- Ensured proper handling of set down actions, including clearance and orientation preservation.