When LB_MOBILE_UI is set, the desktop start screen is replaced by a phone
intent picker: a 2x3 grid of icon cards (Draw / Animate / Compose / Record /
Edit video / Blank) taking the top ~2/3, and a scrollable Recent-projects list
in the bottom ~1/3.
Each intent reuses EditorApp::create_new_project_with_focus and then sets the
initial stack window (e.g. Draw -> fullscreen Stage, Compose -> Timeline +
Piano Roll + Keys). Recent rows load the project and enter the editor. Cards are
icon-only (Lucide glyph + label) for legibility on a phone. Adds the intent
icons to the Lucide set.
Bundle Lucide (ISC license) at assets/fonts/lucide.ttf and register it as the
egui font family "lucide" via mobile/icons.rs::install (called in EditorApp::new).
Icons are drawn as text with icons::font(size) + PUA codepoint constants.
Switch the stack headers (grip, maximize/minimize, node⇄instrument), the footer
chevron, and the transport play/pause to Lucide glyphs instead of relying on
egui's limited built-in emoji-icon-font.
Skyler Lehmkuhl