fix: truncate long approval prefixes when rendering (#8734)

Fixes inscrutable multiline approval requests:
<img width="686" height="844" alt="image"
src="https://github.com/user-attachments/assets/cf9493dc-79e6-4168-8020-0ef0fe676d5e"
/>

codex-rs/tui/src/bottom_pane/approval_overlay.rs

@@ -461,9 +461,13 @@ fn exec_options(
     .chain(
         proposed_execpolicy_amendment
             .filter(|_| features.enabled(Feature::ExecPolicy))
-            .map(|prefix| {
+            .and_then(|prefix| {
                 let rendered_prefix = strip_bash_lc_and_escape(prefix.command());
-                ApprovalOption {
+                if rendered_prefix.contains('\n') || rendered_prefix.contains('\r') {
+                    return None;
+                }
+
+                Some(ApprovalOption {
                     label: format!(
                         "Yes, and don't ask again for commands that start with `{rendered_prefix}`"
                     ),
@@ -474,7 +478,7 @@ fn exec_options(
                     ),
                     display_shortcut: None,
                     additional_shortcuts: vec![key_hint::plain(KeyCode::Char('p'))],
-                }
+                })
             }),
     )
     .chain([ApprovalOption {