feat: add selectable icon styles

crates/app/src/storage.rs

@@ -96,5 +96,26 @@ mod tests {
             "https://gitea.example.com|octo/demo"
         );
         assert_eq!(Preferences::default().pull_status, "open");
+        assert_eq!(
+            Preferences::default().icon_style,
+            crate::domain::IconStyle::Outline
+        );
+        assert_eq!(
+            serde_json::from_str::<Preferences>(r#"{"icon_style":"duotone"}"#)
+                .unwrap()
+                .icon_style,
+            crate::domain::IconStyle::Duotone
+        );
+        assert_eq!(
+            serde_json::from_str::<Preferences>(r#"{"icon_style":"future-style"}"#)
+                .unwrap()
+                .icon_style,
+            crate::domain::IconStyle::Outline
+        );
+        assert_eq!(
+            crate::domain::IconStyle::from_index(2),
+            Some(crate::domain::IconStyle::Bold)
+        );
+        assert_eq!(crate::domain::IconStyle::from_index(3), None);
     }
 }