Add Lucide icon font for the mobile UI

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.

lightningbeam-ui/lightningbeam-editor/assets/fonts/LICENSE-lucide.txt

@@ -0,0 +1,43 @@
+ISC License
+
+Copyright (c) 2026 Lucide Icons and Contributors
+
+Permission to use, copy, modify, and/or distribute this software for any
+purpose with or without fee is hereby granted, provided that the above
+copyright notice and this permission notice appear in all copies.
+
+THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+---
+
+The following Lucide icons are derived from the Feather project:
+
+airplay, alert-circle, alert-octagon, alert-triangle, aperture, arrow-down-circle, arrow-down-left, arrow-down-right, arrow-down, arrow-left-circle, arrow-left, arrow-right-circle, arrow-right, arrow-up-circle, arrow-up-left, arrow-up-right, arrow-up, at-sign, calendar, cast, check, chevron-down, chevron-left, chevron-right, chevron-up, chevrons-down, chevrons-left, chevrons-right, chevrons-up, circle, clipboard, clock, code, columns, command, compass, corner-down-left, corner-down-right, corner-left-down, corner-left-up, corner-right-down, corner-right-up, corner-up-left, corner-up-right, crosshair, database, divide-circle, divide-square, dollar-sign, download, external-link, feather, frown, hash, headphones, help-circle, info, italic, key, layout, life-buoy, link-2, link, loader, lock, log-in, log-out, maximize, meh, minimize, minimize-2, minus-circle, minus-square, minus, monitor, moon, more-horizontal, more-vertical, move, music, navigation-2, navigation, octagon, pause-circle, percent, plus-circle, plus-square, plus, power, radio, rss, search, server, share, shopping-bag, sidebar, smartphone, smile, square, table-2, tablet, target, terminal, trash-2, trash, triangle, tv, type, upload, x-circle, x-octagon, x-square, x, zoom-in, zoom-out
+
+The MIT License (MIT) (for the icons listed above)
+
+Copyright (c) 2013-present Cole Bemis
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

lightningbeam-ui/lightningbeam-editor/src/main.rs

@@ -1207,6 +1207,9 @@ impl EditorApp {
     ) -> Self {
         let current_layout = layouts[0].layout.clone();
 
+        // Register the bundled Lucide icon font (used by the mobile UI; harmless on desktop).
+        mobile::icons::install(&cc.egui_ctx);
+
         // Disable egui's "Unaligned" debug overlay (on by default in debug builds)
         #[cfg(debug_assertions)]
         cc.egui_ctx.style_mut(|style| style.debug.show_unaligned = false);

lightningbeam-ui/lightningbeam-editor/src/mobile/icons.rs

@@ -0,0 +1,47 @@
+//! Lucide icon font (ISC license — see `assets/fonts/LICENSE-lucide.txt`).
+#![allow(dead_code)] // a forward-looking icon palette; not all are wired up yet
+//!
+//! The font is embedded and registered as a named egui font family ("lucide"). Icons are drawn as
+//! text using [`font`] for the `FontId`, with the codepoint constants below (Lucide's private-use
+//! area). Run [`install`] once at startup.
+
+use std::sync::Arc;
+
+use eframe::egui;
+
+/// The egui font-family name the Lucide glyphs live under.
+pub const FAMILY: &str = "lucide";
+
+/// Embed + register the Lucide icon font. Call once with the egui context at startup.
+pub fn install(ctx: &egui::Context) {
+    let mut fonts = egui::FontDefinitions::default();
+    fonts.font_data.insert(
+        "lucide".to_owned(),
+        Arc::new(egui::FontData::from_static(include_bytes!(
+            "../../assets/fonts/lucide.ttf"
+        ))),
+    );
+    fonts
+        .families
+        .insert(egui::FontFamily::Name(FAMILY.into()), vec!["lucide".to_owned()]);
+    ctx.set_fonts(fonts);
+}
+
+/// A `FontId` in the Lucide family at `size`.
+pub fn font(size: f32) -> egui::FontId {
+    egui::FontId::new(size, egui::FontFamily::Name(FAMILY.into()))
+}
+
+// --- Codepoints (Lucide PUA). Add more as the mobile UI needs them. ---
+pub const MAXIMIZE: &str = "\u{e112}";
+pub const MINIMIZE: &str = "\u{e11a}";
+pub const ARROW_LEFT_RIGHT: &str = "\u{e24a}";
+pub const GRIP_HORIZONTAL: &str = "\u{e0ea}";
+pub const CHEVRONS_UP: &str = "\u{e074}";
+pub const PLAY: &str = "\u{e13c}";
+pub const PAUSE: &str = "\u{e12e}";
+pub const SETTINGS: &str = "\u{e154}";
+pub const SEARCH: &str = "\u{e151}";
+pub const PLUS: &str = "\u{e13d}";
+pub const X: &str = "\u{e1b2}";
+pub const MENU: &str = "\u{e115}";

lightningbeam-ui/lightningbeam-editor/src/mobile/mod.rs

@@ -17,6 +17,7 @@ use lightningbeam_core::pane::PaneType;
 use crate::panes::NodePath;
 use crate::RenderContext;
 
+pub mod icons;
 mod stack;
 mod surface;
 mod transport;

lightningbeam-ui/lightningbeam-editor/src/mobile/stack.rs

@@ -18,7 +18,7 @@
 
 use eframe::egui;
 
-use super::{slot_path, MobileState, StackDrag, StackPane, STACK};
+use super::{icons, slot_path, MobileState, StackDrag, StackPane, STACK};
 use crate::RenderContext;
 
 const N: usize = STACK.len();
@@ -242,33 +242,35 @@ fn draw_header(ui: &egui::Ui, hr: egui::Rect, sp: StackPane, show_instruments: b
     p.rect_filled(hr, 0.0, C_HEADER);
     p.hline(hr.x_range(), hr.bottom(), egui::Stroke::new(1.0, C_LINE));
     let cy = hr.center().y;
-    // Grip dots on the left.
+    // Grip glyph on the left (Lucide).
-    for i in 0..2 {
-        let x = hr.left() + 11.0 + i as f32 * 4.0;
-        p.circle_filled(egui::pos2(x, cy), 1.5, C_DIM);
-    }
     p.text(
-        egui::pos2(hr.left() + 26.0, cy),
+        egui::pos2(hr.left() + 15.0, cy),
+        egui::Align2::CENTER_CENTER,
+        icons::GRIP_HORIZONTAL,
+        icons::font(16.0),
+        C_DIM,
+    );
+    p.text(
+        egui::pos2(hr.left() + 32.0, cy),
         egui::Align2::LEFT_CENTER,
         sp.label(show_instruments),
         egui::FontId::proportional(15.0),
         C_BRIGHT,
     );
     // Right-side buttons: fullscreen / restore rightmost, Node/Instrument toggle just left of it.
-    // These glyphs are covered by egui's bundled emoji-icon-font (⛶ ▣ ⇄).
     p.text(
         egui::pos2(hr.right() - BTN_W * 0.5, cy),
         egui::Align2::CENTER_CENTER,
-        if fullscreen { "▣" } else { "⛶" },
+        if fullscreen { icons::MINIMIZE } else { icons::MAXIMIZE },
-        egui::FontId::proportional(18.0),
+        icons::font(17.0),
         C_DIM,
     );
     if sp == StackPane::NodeInstrument {
         p.text(
             egui::pos2(hr.right() - BTN_W * 1.5, cy),
             egui::Align2::CENTER_CENTER,
-            "⇄",
+            icons::ARROW_LEFT_RIGHT,
-            egui::FontId::proportional(17.0),
+            icons::font(17.0),
             C_AMBER,
         );
     }
@@ -279,13 +281,23 @@ fn draw_footer(ui: &egui::Ui, fr: egui::Rect, at_end: bool) {
     p.rect_filled(fr, 0.0, C_HEADER);
     p.hline(fr.x_range(), fr.top(), egui::Stroke::new(1.0, C_LINE));
     let col = if at_end { C_LINE } else { C_DIM };
-    p.text(
+    let cy = fr.center().y;
-        fr.center(),
+    let galley = p.layout_no_wrap(
-        egui::Align2::CENTER_CENTER,
+        "pull up for more".to_string(),
-        "▲  pull up for more",
         egui::FontId::proportional(11.0),
         col,
     );
+    let total_w = 22.0 + galley.size().x;
+    let start_x = fr.center().x - total_w * 0.5;
+    p.text(
+        egui::pos2(start_x + 8.0, cy),
+        egui::Align2::CENTER_CENTER,
+        icons::CHEVRONS_UP,
+        icons::font(14.0),
+        col,
+    );
+    let gy = cy - galley.size().y * 0.5;
+    p.galley(egui::pos2(start_x + 22.0, gy), galley, col);
 }
 
 fn handle_key(h: Handle) -> (usize, usize) {

lightningbeam-ui/lightningbeam-editor/src/mobile/transport.rs

@@ -3,6 +3,7 @@
 
 use eframe::egui;
 
+use super::icons;
 use crate::panes::SharedPaneState;
 
 const C_PANEL: egui::Color32 = egui::Color32::from_rgb(0x1f, 0x24, 0x2c);
@@ -24,12 +25,12 @@ pub fn render(ui: &mut egui::Ui, rect: egui::Rect, shared: &mut SharedPaneState)
     let btn_rect = egui::Rect::from_center_size(btn_center, egui::vec2(btn_r * 2.0, btn_r * 2.0));
     let btn_resp = ui.interact(btn_rect, ui.id().with("mobile_transport_play"), egui::Sense::click());
     painter.circle_filled(btn_center, btn_r, C_AMBER);
-    let glyph = if *shared.is_playing { "⏸" } else { "▶" };
+    let glyph = if *shared.is_playing { icons::PAUSE } else { icons::PLAY };
     painter.text(
         btn_center,
         egui::Align2::CENTER_CENTER,
         glyph,
-        egui::FontId::proportional(16.0),
+        icons::font(16.0),
         C_DARK,
     );
     if btn_resp.clicked() {