Formalize scene viewport chrome and presentation helpers

docs/plan/SceneViewport_Overlay_Gizmo_Rework_Checkpoint_2026-04-02.md

@@ -1,5 +1,27 @@
 # SceneViewport Overlay/Gizmo Rework Checkpoint
 
+## Update 2026-04-04 Phase 5G
+
+### Chrome/Focus/Presentation Shell Formalization Completed
+
+- Added `SceneViewportChrome.{h,cpp}` to take over the remaining scene viewport chrome responsibilities:
+  - top toolbar rendering
+  - in-viewport tool overlay rendering
+  - unified tool-change command building and execution
+- Extended `SceneViewportInteractionFrame.h` with explicit helpers for:
+  - post-interaction viewport focus decisions
+  - final scene viewport presentation refresh and HUD draw
+- `SceneViewPanel` no longer owns inline scene toolbar/tool overlay rendering, ad-hoc tool switching glue, focus heuristics, or the final gizmo refresh/HUD presentation tail path.
+- Added focused editor tests covering tool-command composition/execution and the new focus/presentation helpers.
+
+### Verification
+
+- `cmake --build build --config Debug --target editor_tests -- /p:BuildProjectReferences=false`
+- `build/tests/Editor/Debug/editor_tests.exe --gtest_filter=SceneViewportChromeTest.*:SceneViewportNavigationTest.*:SceneViewportInteractionFrameTest.*:SceneViewportInteractionActionsTest.*:SceneViewportInteractionResolverTest.*:SceneViewportTransformGizmoCoordinatorTest.*:SceneViewportOverlayRenderer_Test.*:SceneViewportOverlayProviderRegistryTest.*:ViewportRenderFlowUtilsTest.*`
+- `cmake --build build --config Debug --target XCEditor`
+
+All commands completed successfully in `Debug`.
+
 ## Update 2026-04-04 Phase 5F
 
 ### Interaction Frame/Request Glue Formalization Completed