UiState gains interfaceScale (percent, 100 = Auto, 75–200), saved in
ui.json and applied as egui's zoom factor on top of the desktop scale.
New UI command view.interfaceScale {percent | "auto"} clamps hostile
values; a malformed saved value reads as 100. View tab gets an
"Interface size" picker. egui's built-in keyboard zoom is turned off so the
preference owns the zoom.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
vangel76