Add /review to main commands (#4416)

<img width="517" height="249" alt="Screenshot 2025-09-28 at 4 33 26 PM"
src="https://github.com/user-attachments/assets/6d34734e-fe3c-4b88-8239-a6436bcb9fa5"
/>

codex-rs/tui/src/history_cell.rs

@@ -414,6 +414,11 @@ pub(crate) fn new_session_info(
                 "/model".into(),
                 " - choose what model and reasoning effort to use".dim(),
             ]),
+            Line::from(vec![
+                "  ".into(),
+                "/review".into(),
+                " - review any changes and find issues".dim(),
+            ]),
         ];
 
         CompositeHistoryCell {