With Preferences > General > Animated Zoom on (the default), a Zoom tool
press held still past 0.3 s zooms continuously about the press point
(2 doublings a second, frame-rate independent, within the zoom_levels
range) until release; Alt zooms out. The release is then no click step.
A quick click still steps, Scrubby Zoom and the zoom rectangle are
unchanged, and with the preference off a hold is one click step.
The hold logic lives in the new zoom_hold.rs; canvas.rs only calls it.
general.animatedZoom leaves HIDDEN_UNTIL_IMPLEMENTED; prefs that do
nothing 25 of 166.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
