The Artboard tool and the Artboards panel only ever had one artboard
selected, so Shift-clicking another didn't add it. As in Illustrator:
- Artboard tool: Shift-click adds an artboard to the selection (it
becomes active) or takes one out; a plain click on a selected one keeps
the selection, so a drag moves them all (Alt copies them all, the
copies becoming the selection), and Delete removes them all, one
artboard always staying. The other selected artboards show dashed
bounds; `selected` is a tool option.
- Artboards panel: with the Artboard tool, Shift- or Ctrl/Cmd-click on a
row adds or removes it, every selected row is highlighted, and Delete
Artboard removes them all.
- `artboard.move` and `artboard.delete` take `indices` besides `index`:
several artboards in one undo step, each with its art (an object moved
once where artboards overlap).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>