Browser: derive Default for rows (clippy)

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01AS5Tn3xieewUSg3uxrMVdL

crates/ui-egui/src/browser.rs

@@ -100,6 +100,7 @@ const ROW_H: f32 = 22.0;
 const INDENT: f32 = 14.0;
 
 /// One row's look.
+#[derive(Default)]
 struct Row<'a> {
     depth: usize,
     /// Some(open) for rows that fold.
@@ -117,12 +118,6 @@ struct Row<'a> {
     badges: &'a [&'a str],
 }
 
-impl Default for Row<'_> {
-    fn default() -> Self {
-        Row { depth: 0, fold: None, eye: None, icon: "", label: "", selected: false, dim: false, color: None, radio: None, badges: &[] }
-    }
-}
-
 /// What happened on a row.
 #[derive(Default)]
 struct RowResp {