- 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.
- Introduced `test_scenery_brick_preview.gd` to validate focused placement and CPU draw-cost for large brick walls.
- Added `test_scenery_surface_cache.gd` to assess texture budget, visual equivalence, and cache invalidation.
- Created `test_scenery_surface_preview.gd` to evaluate adaptive preview selection and placement behavior.
- Implemented various helper functions to measure drawing performance and validate expected behaviors during tests.
- Added unique identifiers for new test files to ensure proper tracking and management.
- Implemented StageSurfaceColorDialog for custom color selection with live preview.
- Created StageBackgroundGround class for non-walkable scenery behind the set.
- Introduced StageRectSurface for shared rectangular geometry and tint preview.
- Added StageSurfacePreview for rendering surface previews.
- Developed comprehensive tests for surface color selection, rendering, and serialization.
ryan