Key node 1: move main-window UI presentation onto the D3D12 render loop with native UI renderer, text system, and texture host.
Key node 2: wire frame timing/FPS display, window runtime, swapchain presentation, and native screenshot capture around the new path.
Key node 3: carry editor shell/workspace/viewport/panel interaction updates needed by the new renderer and detached window flow.
Key node 4: pump async resource loads and scene bridge follow-up needed for scene content visibility in new_editor.
