Bundle Newsreader serif and apply to hero text

Embeds Newsreader (variable opsz/wght, OFL-licensed) into the
ely_app binary via include_bytes!, registers it through GPUI's
text_system at startup (chrome::typography::register_serif_fonts),
and exposes the SERIF_FAMILY constant for downstream surfaces.

Apply the family to every page hero where the design uses
ely-serif: home headline, settings/appearance headline, plugin
marketplace headline, sync headline, plugin detail name, and the
home reading-list cover headline. The OFL license file ships
alongside the .ttf assets to satisfy the font's redistribution
clause.

crates/ely_app/src/shell/chrome/typography.rs

@@ -0,0 +1,17 @@
+use std::borrow::Cow;
+
+use gpui::App;
+
+const NEWSREADER_REGULAR: &[u8] =
+    include_bytes!("../../../assets/fonts/Newsreader.ttf");
+const NEWSREADER_ITALIC: &[u8] =
+    include_bytes!("../../../assets/fonts/Newsreader-Italic.ttf");
+
+pub(crate) const SERIF_FAMILY: &str = "Newsreader";
+
+pub(crate) fn register_serif_fonts(cx: &App) -> gpui::Result<()> {
+    cx.text_system().add_fonts(vec![
+        Cow::Borrowed(NEWSREADER_REGULAR),
+        Cow::Borrowed(NEWSREADER_ITALIC),
+    ])
+}