Restructure settings landing as design's nav + content split

Settings now opens with the design's two-column layout: a 232 wide nav
column on the left with grouped sections (General, Account, Power,
About) and a content column on the right that leads with a serif
headline, snapshot metric cards, and a "Jump in" list of every settings
route. Each nav entry and jump row deep-links to the existing internal
page so the destinations remain real.

The previous settings.rs is now a thin shim that calls into the chrome
module — keeps the module under 500 lines and lets future
sub-page redesigns share the same shell layout.

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

@@ -1,5 +1,6 @@
 pub(crate) mod command_overlay;
 pub(crate) mod home;
+pub(crate) mod settings_layout;
 pub(crate) mod sidebar;
 pub(crate) mod sidebar_header;
 pub(crate) mod topbar;
@@ -7,6 +8,7 @@ pub(crate) mod wallpaper;
 
 pub(crate) use command_overlay::render_command_overlay;
 pub(crate) use home::render_home_page;
+pub(crate) use settings_layout::render_settings_landing;
 pub(crate) use sidebar::{PANEL_BG, panel_shadow};
 pub(crate) use sidebar_header::render_sidebar_header;
 pub(crate) use topbar::render_topbar;