tui: bring the transcript closer to display mode (#4848)

before
<img width="1161" height="836" alt="Screenshot 2025-10-06 at 3 06 52 PM"
src="https://github.com/user-attachments/assets/7622fd6b-9d37-402f-8651-61c2c55dcbc6"
/>

after
<img width="1161" height="858" alt="Screenshot 2025-10-06 at 3 07 02 PM"
src="https://github.com/user-attachments/assets/1498f327-1d1a-4630-951f-7ca371ab0139"
/>

codex-rs/tui/src/app_backtrack.rs

@@ -134,8 +134,9 @@ impl App {
     /// Useful when switching sessions to ensure prior history remains visible.
     pub(crate) fn render_transcript_once(&mut self, tui: &mut tui::Tui) {
         if !self.transcript_cells.is_empty() {
+            let width = tui.terminal.last_known_screen_size.width;
             for cell in &self.transcript_cells {
-                tui.insert_history_lines(cell.transcript_lines());
+                tui.insert_history_lines(cell.display_lines(width));
             }
         }
     }