fix: wrap long exec lines in transcript overlay (#7481)

What
-----
- Fix the Ctrl+T transcript overlay so that very long exec output lines
are soft‑wrapped to the viewport width instead of being rendered as a
single truncated row.
- Add a regression test to `TranscriptOverlay` to ensure long exec
outputs are rendered on multiple lines in the overlay.

Why
----
- Previously, the transcript overlay rendered extremely long single exec
lines as one on‑screen row and simply cut them off at the right edge,
with no horizontal scrolling.
- This made it impossible to inspect the full content of long tool/exec
outputs in the transcript view, even though the main TUI view already
wrapped those lines.
- Fixes #7454.

How
----
- Update `ExecCell::transcript_lines` to wrap exec output lines using
the existing `RtOptions`/`word_wrap_line` helpers so that transcript
rendering is width‑aware.
- Reuse the existing line utilities to expand the wrapped `Line` values
into the transcript overlay, preserving styling while respecting the
current viewport width.
- Add `transcript_overlay_wraps_long_exec_output_lines` test in
`pager_overlay.rs` that constructs a long single‑line exec output,
renders the transcript overlay into a small buffer, and asserts that the
long marker string spans multiple rendered lines.

codex-rs/tui/src/pager_overlay.rs

@@ -748,6 +748,49 @@ mod tests {
         assert_snapshot!("transcript_overlay_apply_patch_scroll_vt100", snapshot);
     }
 
+    #[test]
+    fn transcript_overlay_wraps_long_exec_output_lines() {
+        let marker = "Z";
+        let long_line = marker.repeat(200);
+
+        let mut exec_cell = crate::exec_cell::new_active_exec_command(
+            "exec-long".into(),
+            vec!["bash".into(), "-lc".into(), "echo long".into()],
+            vec![ParsedCommand::Unknown {
+                cmd: "echo long".into(),
+            }],
+            ExecCommandSource::Agent,
+            None,
+            false,
+        );
+        exec_cell.complete_call(
+            "exec-long",
+            CommandOutput {
+                exit_code: 0,
+                aggregated_output: format!("{long_line}\n"),
+                formatted_output: long_line,
+            },
+            Duration::from_millis(10),
+        );
+        let exec_cell: Arc<dyn HistoryCell> = Arc::new(exec_cell);
+
+        let mut overlay = TranscriptOverlay::new(vec![exec_cell]);
+        let area = Rect::new(0, 0, 20, 10);
+        let mut buf = Buffer::empty(area);
+
+        overlay.render(area, &mut buf);
+        let rendered = buffer_to_text(&buf, area);
+
+        let wrapped_lines = rendered
+            .lines()
+            .filter(|line| line.contains(marker))
+            .count();
+        assert!(
+            wrapped_lines >= 2,
+            "expected long exec output to wrap into multiple lines in transcript overlay, got:\n{rendered}"
+        );
+    }
+
     #[test]
     fn transcript_overlay_keeps_scroll_pinned_at_bottom() {
         let mut overlay = TranscriptOverlay::new(