Pressing with Shift on an object that was already selected toggled it
out of the selection at once and went idle, so the drag that followed
moved nothing. The toggle now waits for the release: a Shift-click
still takes the object out of the selection, while a Shift-drag moves
the selection constrained, as it already did for unselected objects
and when Shift was pressed mid-drag.
Fixes#224.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01U9TrG4w49oSRYbP3cqxA3D
theironchefandClaude Opus 5.5
80eb5844c7