- Implemented `test_editor_visual_harmonization.gd` to validate the Stickman editor and prop editor UI layouts, ensuring proper functionality and visual consistency.
- Created `test_editor_visual_theme.gd` to verify the loading and application of visual themes in the editor, including semantic overrides and default values.
- Introduced `test_phase19_ground_finish_chooser.gd` to test the ground finish chooser's functionality, including layout responsiveness, selection behavior, and interaction with the stage.
- Added new scripts for ground finish preview and chooser UI components to enhance the editor's visual representation of ground finishes.
- Implemented StageBackgroundView class for managing sky and plain backgrounds in the stage.
- Added functionality to set background type and color, bind camera, and apply themes.
- Created test_phase19_plain_background.gd to validate plain background behavior and migration.
- Developed test_phase19_starter_chooser_layout.gd to ensure proper layout and functionality of the starter chooser.
- Included visual capture tests for UI elements and interactions.