chore: merge name and title (#17116)

Merge title and name concept to leverage the sqlite title column and
have more efficient queries

---------

Co-authored-by: Codex <noreply@openai.com>

codex-rs/state/src/extract.rs

@@ -33,7 +33,9 @@ pub fn apply_rollout_item(
 pub fn rollout_item_affects_thread_metadata(item: &RolloutItem) -> bool {
     match item {
         RolloutItem::SessionMeta(_) | RolloutItem::TurnContext(_) => true,
-        RolloutItem::EventMsg(EventMsg::TokenCount(_) | EventMsg::UserMessage(_)) => true,
+        RolloutItem::EventMsg(
+            EventMsg::TokenCount(_) | EventMsg::UserMessage(_) | EventMsg::ThreadNameUpdated(_),
+        ) => true,
         RolloutItem::EventMsg(_) | RolloutItem::ResponseItem(_) | RolloutItem::Compacted(_) => {
             false
         }
@@ -95,13 +97,18 @@ fn apply_event_msg(metadata: &mut ThreadMetadata, event: &EventMsg) {
                 }
             }
         }
+        EventMsg::ThreadNameUpdated(updated) => {
+            if let Some(title) = updated.thread_name.as_deref()
+                && !title.trim().is_empty()
+            {
+                metadata.title = title.trim().to_string();
+            }
+        }
         _ => {}
     }
 }
 
-fn apply_response_item(_metadata: &mut ThreadMetadata, _item: &ResponseItem) {
-    // Title and first_user_message are derived from EventMsg::UserMessage only.
-}
+fn apply_response_item(_metadata: &mut ThreadMetadata, _item: &ResponseItem) {}
 
 fn strip_user_message_prefix(text: &str) -> &str {
     match text.find(USER_MESSAGE_BEGIN) {
@@ -152,6 +159,7 @@ mod tests {
     use codex_protocol::protocol::SessionMeta;
     use codex_protocol::protocol::SessionMetaLine;
     use codex_protocol::protocol::SessionSource;
+    use codex_protocol::protocol::ThreadNameUpdatedEvent;
     use codex_protocol::protocol::TurnContextItem;
     use codex_protocol::protocol::USER_MESSAGE_BEGIN;
     use codex_protocol::protocol::UserMessageEvent;
@@ -198,6 +206,25 @@ mod tests {
         assert_eq!(metadata.title, "actual user request");
     }
 
+    #[test]
+    fn thread_name_update_replaces_title_without_changing_first_user_message() {
+        let mut metadata = metadata_for_test();
+        metadata.title = "actual user request".to_string();
+        metadata.first_user_message = Some("actual user request".to_string());
+        let item = RolloutItem::EventMsg(EventMsg::ThreadNameUpdated(ThreadNameUpdatedEvent {
+            thread_id: metadata.id,
+            thread_name: Some("saved-session".to_string()),
+        }));
+
+        apply_rollout_item(&mut metadata, &item, "test-provider");
+
+        assert_eq!(
+            metadata.first_user_message.as_deref(),
+            Some("actual user request")
+        );
+        assert_eq!(metadata.title, "saved-session");
+    }
+
     #[test]
     fn event_msg_image_only_user_message_sets_image_placeholder_preview() {
         let mut metadata = metadata_for_test();