forked from 1b-agent/opencadstudio-upstream
Detect the desktop's configured interface font and use its family for all application UI text, instead of iced's generic sans-serif. - sys::ui_font reads the setting per platform: GNOME/Cinnamon/MATE gsettings, KDE kdeglobals, Xfce xfconf, the XDG Settings portal, GTK settings.ini and a Fontconfig fallback on Linux; the non-client message font (SystemParametersInfoForDpi at 96 DPI) on Windows; the AppKit system font on macOS. - ui_font::apply remaps generic sans-serif in iced's shared font database to that family. iced's Font::DEFAULT is sans-serif, so every widget, canvas text, bold/italic variant and ribbon measurement follows it with no call-site changes. A family that is not installed (or a generic alias) keeps iced's own choice. The font's weight and style are ignored. - Live updates: portal SettingChanged on Linux, a 2 s poll on Windows. A change bumps the font-system version so laid-out text reshapes, and iced::font::set_defaults relays out every window; ribbon large-button widths re-measure. Without a portal, Linux needs a restart; macOS has no user-adjustable UI font. - Monospaced text, drawing text (own cosmic-text font systems) and the web build's font loading are unchanged. Co-Authored-By: Claude Opus 5.5 <[email protected]>