Fix queued messages during /review (#9122)

Sending a message during /review interrupts the review, whereas during
normal operation, sending a message while the agent is running will
queue the message. This is unexpected behavior, and since /review
usually takes a while, it takes away a potentially useful operation.

Summary
- Treat review mode as an active task for message queuing so inputs
don’t inject into the running review turn.
- Prevents user submissions from rendering immediately in the transcript
while the review continues streaming.
- Keeps review UX consistent with normal “task running” behavior and
avoids accidental interrupt/replacement.

Notes
- This change only affects UI queuing logic; core review flow and task
lifecycle remain unchanged.

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

@@ -3871,3 +3871,33 @@ async fn chatwidget_tall() {
     .unwrap();
     assert_snapshot!(term.backend().vt100().screen().contents());
 }
+
+#[tokio::test]
+async fn review_queues_user_messages_snapshot() {
+    let (mut chat, mut rx, _op_rx) = make_chatwidget_manual(None).await;
+
+    chat.handle_codex_event(Event {
+        id: "review-1".into(),
+        msg: EventMsg::EnteredReviewMode(ReviewRequest {
+            target: ReviewTarget::UncommittedChanges,
+            user_facing_hint: Some("current changes".to_string()),
+        }),
+    });
+    let _ = drain_insert_history(&mut rx);
+
+    chat.queue_user_message(UserMessage::from(
+        "Queued while /review is running.".to_string(),
+    ));
+
+    let width: u16 = 80;
+    let height: u16 = 18;
+    let backend = VT100Backend::new(width, height);
+    let mut term = crate::custom_terminal::Terminal::with_options(backend).expect("terminal");
+    let desired_height = chat.desired_height(width).min(height);
+    term.set_viewport_area(Rect::new(0, height - desired_height, width, desired_height));
+    term.draw(|f| {
+        chat.render(f.area(), f.buffer_mut());
+    })
+    .unwrap();
+    assert_snapshot!(term.backend().vt100().screen().contents());
+}