feat: Set chat name (#4974)

Set chat name with `/name` so they appear in the codex resume page:


https://github.com/user-attachments/assets/c0252bba-3a53-44c7-a740-f4690a3ad405

codex-rs/core/src/codex.rs

@@ -88,6 +88,7 @@ use crate::protocol::ReviewDecision;
 use crate::protocol::ReviewOutputEvent;
 use crate::protocol::SandboxPolicy;
 use crate::protocol::SessionConfiguredEvent;
+use crate::protocol::SessionRenamedEvent;
 use crate::protocol::StreamErrorEvent;
 use crate::protocol::Submission;
 use crate::protocol::TokenCountEvent;
@@ -1507,6 +1508,16 @@ async fn submission_loop(
                 };
                 sess.send_event(event).await;
             }
+            Op::SetSessionName { name } => {
+                // Persist a rename event and notify the client. We rely on the
+                // recorder's filtering to include this in the rollout.
+                let sub_id = sub.id.clone();
+                let event = Event {
+                    id: sub_id,
+                    msg: EventMsg::SessionRenamed(SessionRenamedEvent { name }),
+                };
+                sess.send_event(event).await;
+            }
             Op::Review { review_request } => {
                 spawn_review_thread(
                     sess.clone(),