Introduce a switchable UI stack so the original Slate widget stays available
as a fallback while the new CodeDesign-inspired redesign and a future UMG
Widget Blueprint implementation coexist.
- PS_Editor_MainWidget_Legacy: pre-refactor Slate widget, restored from HEAD
- PS_Editor_MainWidget: refactored floating-HUD Slate widget with style asset,
9-slice panels/buttons, rounded brushes, icon pack, Play/Pause/Stop icons,
spec-aligned palette and radii, File dropdown, outliner per-item icons,
command palette
- PS_Editor_MainWidget_UMG: abstract base class exposing a Blueprint-callable
API (SetTransformMode, SaveScenario, Simulate, Selection...) and delegates
(OnToolChanged, OnSelectionChanged...) so a WBP deriving from it can drive
the editor end-to-end
- APS_Editor_HUD: UIMode enum + UMGWidgetClass soft ref, picks the right
widget at BeginPlay; separate typed accessors for each flavor
Adds UI style system (UPS_Editor_UIStyleAsset DataAsset + FPS_Editor_UIStyle
helper) with runtime PNG loading for icons and 9-slice brushes from
Content/UI/icons/ and Content/UI/unreal_9slice/.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>