Double-clicking a mask or shape path's point (or segment) put its points
in a free-transform box but left only the clicked point selected, so
once the box was gone a drag moved that one point. As in After Effects,
the double-click now selects all the path's points too: dragging inside
the box, or afterwards any of the points, moves the whole mask.
The test also draws a mask with the Pen, moves a point and undoes: each
undo takes back one action (the move, the closing, the last point).
Test: pen_mask_undoes_step_by_step_and_double_click_moves_the_whole_mask
(ui_viewer).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
