While a group or layer was isolated, clicks, hovers and drags still
reached the art outside it, and that art drew as usual. Now only the
isolated container's contents hit: the art around it is locked and
clicks pass through it. On the canvas it draws at half opacity, above
the group as well as below, each run of it as one dimmed layer.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>