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/internal_pages/plugin_details.rs

@@ -10,6 +10,7 @@ use gpui_component::{
 };
 
 use super::{ElyShell, render_canvas_surface};
+use crate::shell::chrome::SERIF_FAMILY;
 
 impl ElyShell {
     pub(super) fn render_plugin_detail_page(
@@ -75,7 +76,8 @@ impl ElyShell {
                     .gap_2()
                     .child(
                         div()
-                            .text_size(px(26.0))
+                            .font_family(SERIF_FAMILY)
+                            .text_size(px(28.0))
                             .truncate()
                             .text_color(rgb(colors::INK))
                             .child(plugin.manifest().name().to_string()),