Stretching a grip now drags the grips of the other selected objects that sit
on the same point, so connected lines stay connected, and the Move, Rotate,
Scale and Mirror grip modes transform every selected object about the hot
grip, as in AutoCAD. grip.move/grip.stretch take the other objects in
`handles`; with only `handle` they edit that object alone, as before.
Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
