Resolve clippy warnings introduced this round

- AppearanceSettings derives Default instead of carrying a manual impl
  that's identical to the derived one.
- topbar::render_lock_or_search collapses the duplicated Search arms
  into a single fallback so clippy stops flagging identical blocks.
- command_overlay row helpers bundle id/title/hint/keys into a small
  CommandRowContent struct so render_row, render_row_with_glyph, and
  render_row_inner stay under the 7-arg threshold without losing any
  call-site clarity.

crates/ely_domain/src/appearance.rs

@@ -19,23 +19,13 @@ pub enum ThemeMode {
     Dark,
 }
 
-#[derive(Clone, Copy, Debug, Deserialize, Eq, Ord, PartialEq, PartialOrd, Serialize)]
+#[derive(Clone, Copy, Debug, Default, Deserialize, Eq, Ord, PartialEq, PartialOrd, Serialize)]
 pub struct AppearanceSettings {
     wallpaper: WallpaperTheme,
     theme_mode: ThemeMode,
     reduce_motion: bool,
 }
 
-impl Default for AppearanceSettings {
-    fn default() -> Self {
-        Self {
-            wallpaper: WallpaperTheme::default(),
-            theme_mode: ThemeMode::default(),
-            reduce_motion: false,
-        }
-    }
-}
-
 impl AppearanceSettings {
     pub fn wallpaper(&self) -> WallpaperTheme {
         self.wallpaper