T00 foundation: theme, motion, assets, icon, buttons, gallery

Theme tokens in light and dark with high contrast, a palette cross-fade,
motion curves and a damped spring, embedded Lucide icons with Inter and
JetBrains Mono, Icon, Button, IconButton, and a gallery that captures
its own window. Reviewed by codex gpt-6-astra (max): PASS in round 3.

src/lib.rs

@@ -0,0 +1,24 @@
+mod assets;
+
+pub mod buttons;
+pub mod motion;
+pub mod primitives;
+pub mod theme;
+
+pub use assets::Assets;
+
+use gpui::App;
+
+use crate::primitives::IconName;
+
+/// Loads fonts and the theme. Call once, first.
+pub fn init(cx: &mut App) {
+    let probe = IconName::Check.path();
+    let wired = cx.asset_source().load(probe).ok().flatten().is_some();
+    assert!(
+        wired,
+        "ely: pass `ely_gpui_component::Assets` to `Application::with_assets`"
+    );
+    assets::load_fonts(cx).expect("ely: embedded fonts failed to register");
+    theme::Theme::init(cx);
+}