chore: snapshot editor work and restore tests

Key points:\n- restore the tests tree removed by bc47e6e\n- capture current editor workspace, scene, and docs reshuffle changes\n- keep local cloud.nvdb resources ignored from this commit

editor/app/Windowing/System/EditorWindowSystem.h

@@ -0,0 +1,49 @@
+#pragma once
+
+#include "Composition/EditorWindowWorkspaceStore.h"
+
+#include <XCEditor/Workspace/UIEditorWorkspaceController.h>
+
+#include <string>
+#include <string_view>
+
+namespace XCEngine::UI::Editor::App {
+
+class EditorWindowSystem final {
+public:
+    explicit EditorWindowSystem(UIEditorPanelRegistry panelRegistry);
+
+    const UIEditorPanelRegistry& GetPanelRegistry() const;
+
+    bool BootstrapPrimaryWindow(
+        std::string_view primaryWindowId,
+        const UIEditorWorkspaceController& workspaceController,
+        std::string& outError);
+
+    bool ValidateWindowSet(
+        const UIEditorWindowWorkspaceSet& windowSet,
+        std::string& outError) const;
+    bool TrySetWindowSet(
+        UIEditorWindowWorkspaceSet windowSet,
+        std::string& outError);
+    bool UpsertWindowState(
+        const UIEditorWindowWorkspaceState& windowState,
+        bool primary,
+        std::string& outError);
+    void RemoveWindowState(std::string_view windowId, bool primary);
+    bool IsPrimaryWindowId(std::string_view windowId) const;
+
+    const UIEditorWindowWorkspaceSet& GetWindowSet() const;
+    UIEditorWindowWorkspaceController BuildWorkspaceMutationController() const;
+
+    UIEditorWindowWorkspaceOperationResult EvaluateDetachPanelToNewWindow(
+        std::string_view sourceWindowId,
+        std::string_view sourceNodeId,
+        std::string_view panelId,
+        UIEditorWindowWorkspaceController& outController) const;
+
+private:
+    EditorWindowWorkspaceStore m_workspaceStore;
+};
+
+} // namespace XCEngine::UI::Editor::App