While an opacity mask or a pattern was edited, a Shaper scribble and
Object › Shaper › Release and Expand ended isolation, and a Shaper
double-click on a Shaper Group isolated the group's original shapes.
Each replaced the editing layer's isolation while the document stayed
in mask or pattern editing. A click on the Shaper Group's mode widget
did the same through object.isolate.
A scribble, Release and Expand now keep the editing layer isolated in
these modes, and end isolation as before outside them. A double-click
with Shaper selects the original shape under the pointer without
isolating the group's original shapes, and the mode widget does not
show while a mask or a pattern is edited.
Docs: docs/shaper.md, docs/target-app-parity.md.