Cut workspace panel factory out of windowing

docs/plan/editor-core-refactor-plan.md

@@ -272,6 +272,11 @@ Completed follow-up:
   owns the command-focus sync point between main panels and after-focus panels.
 - Concrete workspace and utility panels use `EditorPanelServices` and no longer
   include `Composition/EditorContext.h`.
+- `app/Windowing/**` no longer accepts or calls
+  `EditorWorkspacePanelRuntimeSetFactory`. `Application` composes
+  `CreateEditorWorkspacePanelRuntimeSet()` with
+  `CreateEditorWorkspaceShellRuntime(...)`, then injects a zero-argument
+  `EditorWorkspaceShellRuntimeFactory` into windowing.
 
 ## Phase 2: Introduce XCEditorCore
 
@@ -476,6 +481,10 @@ Completed cuts:
   `Core/Windowing/EditorWorkspaceShellRuntime.h`. `Application` injects the
   concrete `EditorShellRuntime` factory, and `EditorContext` remains the
   concrete `EditorFrameServices` implementation.
+- The shell-runtime construction hook visible to `app/Windowing/**` is now a
+  zero-argument `EditorWorkspaceShellRuntimeFactory`. Workspace panel runtime
+  set construction stays in `Application`, so windowing no longer sees
+  `EditorWorkspacePanelRuntimeSetFactory`.
 
 ## Phase 6: Documentation Update