Clarify TUI reconnect status for HTTP 429 stream errors (#59253)

## What changed

For live, retryable `ResponseStreamDisconnected` errors with HTTP status `429`, replace `Reconnecting... <attempt>` with `Server is busy, reconnecting <attempt>` in the TUI status header.

## Testing

Update the stream recovery test to assert `Server is busy, reconnecting 2/5` and verify that the previous status is restored when streaming resumes.

GitOrigin-RevId: 7fb97f61b856a830565b86ec1bac2ef8608875b8

codex-rs/tui/src/chatwidget/protocol.rs

@@ -214,10 +214,19 @@ impl ChatWidget {
             ServerNotification::Error(notification) => {
                 if notification.will_retry {
                     if !from_replay {
-                        self.on_stream_error(
-                            notification.error.message,
-                            notification.error.additional_details,
-                        );
+                        let error = notification.error;
+                        let message =
+                            if let Some(AppServerCodexErrorInfo::ResponseStreamDisconnected {
+                                http_status_code: Some(429),
+                            }) = error.codex_error_info
+                                && let Some(attempt) =
+                                    error.message.strip_prefix("Reconnecting... ")
+                            {
+                                format!("Server is busy, reconnecting {attempt}")
+                            } else {
+                                error.message
+                            };
+                        self.on_stream_error(message, error.additional_details);
                     }
                 } else if from_replay || !safety_recourse::defer_error(self, &notification) {
                     self.last_non_retry_error = Some((

codex-rs/tui/src/chatwidget/tests/app_server.rs

@@ -1889,8 +1889,10 @@ async fn live_app_server_stream_recovery_restores_previous_status_header() {
         ServerNotification::Error(ErrorNotification {
             error: AppServerTurnError {
                 misalignment: None,
-                message: "Reconnecting... 1/5".to_string(),
-                codex_error_info: Some(CodexErrorInfo::Other),
+                message: "Reconnecting... 2/5".to_string(),
+                codex_error_info: Some(CodexErrorInfo::ResponseStreamDisconnected {
+                    http_status_code: Some(429),
+                }),
                 additional_details: None,
             },
             will_retry: true,
@@ -1901,6 +1903,11 @@ async fn live_app_server_stream_recovery_restores_previous_status_header() {
     );
     drain_insert_history(&mut rx);
 
+    insta::assert_snapshot!(
+        chat.bottom_pane.status_widget().unwrap().header(),
+        @"Server is busy, reconnecting 2/5"
+    );
+
     chat.handle_server_notification(
         ServerNotification::AgentMessageDelta(
             codex_app_server_protocol::AgentMessageDeltaNotification {