tui: tweaks to dialog display (#4622)

- prefix command approval reasons with "Reason:"
- show keyboard shortcuts for some ListSelectionItems
- remove "description" lines for approval options, and make the labels
more verbose
- add a spacer line in diff display after the path

and some other minor refactors that go along with the above.

<img width="859" height="508" alt="Screenshot 2025-10-02 at 1 24 50 PM"
src="https://github.com/user-attachments/assets/4fa7ecaf-3d3a-406a-bb4d-23e30ce3e5cf"
/>

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

@@ -1236,6 +1236,14 @@ fn approval_modal_exec_snapshot() {
     terminal
         .draw(|f| f.render_widget_ref(&chat, f.area()))
         .expect("draw approval modal");
+    assert!(
+        terminal
+            .backend()
+            .vt100()
+            .screen()
+            .contents()
+            .contains("echo hello world")
+    );
     assert_snapshot!(
         "approval_modal_exec",
         terminal.backend().vt100().screen().contents()
@@ -1261,12 +1269,16 @@ fn approval_modal_exec_without_reason_snapshot() {
     });
 
     let height = chat.desired_height(80);
-    let mut terminal = ratatui::Terminal::new(ratatui::backend::TestBackend::new(80, height))
-        .expect("create terminal");
+    let mut terminal =
+        ratatui::Terminal::new(VT100Backend::new(80, height)).expect("create terminal");
+    terminal.set_viewport_area(Rect::new(0, 0, 80, height));
     terminal
         .draw(|f| f.render_widget_ref(&chat, f.area()))
         .expect("draw approval modal (no reason)");
-    assert_snapshot!("approval_modal_exec_no_reason", terminal.backend());
+    assert_snapshot!(
+        "approval_modal_exec_no_reason",
+        terminal.backend().vt100().screen().contents()
+    );
 }
 
 // Snapshot test: patch approval modal
@@ -1296,12 +1308,16 @@ fn approval_modal_patch_snapshot() {
 
     // Render at the widget's desired height and snapshot.
     let height = chat.desired_height(80);
-    let mut terminal = ratatui::Terminal::new(ratatui::backend::TestBackend::new(80, height))
-        .expect("create terminal");
+    let mut terminal =
+        ratatui::Terminal::new(VT100Backend::new(80, height)).expect("create terminal");
+    terminal.set_viewport_area(Rect::new(0, 0, 80, height));
     terminal
         .draw(|f| f.render_widget_ref(&chat, f.area()))
         .expect("draw patch approval modal");
-    assert_snapshot!("approval_modal_patch", terminal.backend());
+    assert_snapshot!(
+        "approval_modal_patch",
+        terminal.backend().vt100().screen().contents()
+    );
 }
 
 #[test]
@@ -1831,14 +1847,14 @@ fn apply_patch_untrusted_shows_approval_modal() {
         for x in 0..area.width {
             row.push(buf[(x, y)].symbol().chars().next().unwrap_or(' '));
         }
-        if row.contains("Apply changes?") {
+        if row.contains("Would you like to make the following edits?") {
             contains_title = true;
             break;
         }
     }
     assert!(
         contains_title,
-        "expected approval modal to be visible with title 'Apply changes?'"
+        "expected approval modal to be visible with title 'Would you like to make the following edits?'"
     );
 }