Add DesktopComponentRenderMode and thread the render mode through runtime context and creation APIs so controls can be created for library previews. Replace image-based preview system with static preview Controls: viewmodels and ComponentLibraryWindow now use PreviewControl, and ComponentPreviewImageService/related types and tests were removed. Add ComponentPreviewRuntimeQuiescer to attach/detach preview controls (stop timers, disable input) for safe static previews. Simplify component-library collapse state/presenter by removing transient expanded opacity handling. Update runtime registry, services, views and tests to support the new flow.
