Wait for native layout selection repaint in UI capture

tests/chat_profiles.cpp

@@ -320,6 +320,14 @@ int main()
             SendMessageW(lan,WM_TIMER,1,0);
             require(IsDlgButtonChecked(lan,713)==BST_CHECKED,"status refresh preserves unsaved position choice");
             require(!IsWindowEnabled(GetDlgItem(lan,715)),"input cannot start while discovery is disabled");
+            // Let the native radio-button theme animation finish before visual capture.
+            auto repaintUntil=GetTickCount64()+200;
+            while(GetTickCount64()<repaintUntil)
+            {
+                MSG message{};
+                while(PeekMessageW(&message,nullptr,0,0,PM_REMOVE)){TranslateMessage(&message);DispatchMessageW(&message);}
+                Sleep(10);
+            }
             RedrawWindow(lan,nullptr,nullptr,RDW_INVALIDATE|RDW_UPDATENOW|RDW_ALLCHILDREN);
             RECT r{};GetClientRect(lan,&r);HDC dc=GetDC(lan);auto screenshot=ks::screenshotClip(dc,r.right,r.bottom,{});ReleaseDC(lan,dc);
             ks::atomicWrite(std::filesystem::path(ks::executable()).parent_path()/L"lan-screen-layout.png",ks::encodePng(ks::decodeImage(screenshot)));