agent: Allow renaming threads (#28102)

Release Notes:

- agent: Add support for renaming threads

---------

Co-authored-by: Danilo Leal <daniloleal09@gmail.com>
Co-authored-by: Bennet Bo Fenner <bennetbo@gmx.de>
Co-authored-by: Richard Feldman <oss@rtfeldman.com>

crates/agent/src/agent_diff.rs

@@ -238,7 +238,7 @@ impl AgentDiff {
 
     fn handle_thread_event(&mut self, event: &ThreadEvent, cx: &mut Context<Self>) {
         match event {
-            ThreadEvent::SummaryChanged => self.update_title(cx),
+            ThreadEvent::SummaryGenerated => self.update_title(cx),
             _ => {}
         }
     }