pub fn build_fonts(active: FontChoice) -> FontDefinitionsExpand description
Build the egui FontDefinitions for the active
font choice. Every selectable font is registered under its own family name so
the preferences menu can preview each entry in its own typeface.
The UI chrome (nav tree, toolbar, menus, overlays) always renders in Basic
(Roboto): it is pinned first in the Proportional family regardless of the
choice. The canvas renders in the selected font via the dedicated
[CANVAS_FAMILY], which is repointed here — so switching fonts restyles only
the drawn diagram, never the chrome.