Fix a bunch of other low-hanging style lints (#36498)

- **Fix a bunch of low hanging style lints like unnecessary-return**
- **Fix single worktree violation**
- **And the rest**

Release Notes:

- N/A

crates/agent_ui/src/active_thread.rs

@@ -2246,9 +2246,7 @@ impl ActiveThread {
         let after_editing_message = self
             .editing_message
             .as_ref()
-            .map_or(false, |(editing_message_id, _)| {
-                message_id > *editing_message_id
-            });
+            .is_some_and(|(editing_message_id, _)| message_id > *editing_message_id);
 
         let backdrop = div()
             .id(("backdrop", ix))