Comment by ethan_smith

The OCP CAD Viewer extension for VS Code (works with both CadQuery and build123d) gets partway there - you can click on faces/edges in the 3D view and it shows you the selection info you'd need for your code. It's not full "click to generate code" but it helps a lot with the "keeping geometry in my head" problem. Still a long way from the OnShape FeatureScript model where GUI and code are truly bidirectional though.