Use neutral labels for nonzero exits in compact TUI output (#54433)

## What changed

- Show `Exited (status N)` instead of `Failed (exit N)` for compact command output, and remove the red bullet styling.
- Label compact exploration counts as `nonzero exit` or `nonzero exits` instead of `failed`, and remove the red styling from the count.

## Testing

Update snapshots for compact command output and exploration summaries to reflect the new labels and styling.

GitOrigin-RevId: 043593720cc3837ca530d1c008565695abcd5af1

codex-rs/tui/src/chatwidget/tests/snapshots/codex_tui__chatwidget__tests__exec_flow__compact_exploration_with_failures.snap

@@ -3,7 +3,7 @@ source: tui/src/chatwidget/tests/exec_flow.rs
 assertion_line: 175
 expression: "chat.transcript.active_cell.as_ref().unwrap().compact_hyperlink_lines(24).iter().map(|line|\nline.line.to_string()).collect::<Vec<_>>().join(\"\\n\")"
 ---
-• Explored · 4 failed
+• Explored · 4 nonzero …
   └ Read first.txt
     Read missing.txt (e…
          1)

codex-rs/tui/src/exec_cell/compact.rs

@@ -77,9 +77,9 @@ impl ExecCell {
         {
             return Vec::new();
         }
-        let failed = call.output.as_ref().filter(|output| output.exit_code != 0);
-        let marker = if failed.is_some() {
-            "•".red().bold()
+        let nonzero_exit = call.output.as_ref().filter(|output| output.exit_code != 0);
+        let marker = if nonzero_exit.is_some() {
+            "•".bold()
         } else if self.is_active() {
             activity_indicator(
                 call.start_time,
@@ -90,8 +90,8 @@ impl ExecCell {
         } else {
             "•".green().bold()
         };
-        let title = if let Some(output) = failed {
-            format!("Failed (exit {})", output.exit_code)
+        let title = if let Some(output) = nonzero_exit {
+            format!("Exited (status {})", output.exit_code)
         } else if self.is_active() {
             "Running".to_owned()
         } else if call.is_unified_exec_interaction() {

codex-rs/tui/src/exec_cell/render.rs

@@ -241,7 +241,7 @@ impl HistoryCell for ExecCell {
         if self.is_exploring_cell() {
             let mut lines = self.exploring_display_lines(width);
             lines.truncate(1 + crate::history_cell::activity_preview::DETAIL_PREVIEW_LINES);
-            let failures = self
+            let nonzero_exits = self
                 .group
                 .calls
                 .iter()
@@ -251,12 +251,17 @@ impl HistoryCell for ExecCell {
                         .is_some_and(|output| output.exit_code != 0)
                 })
                 .count();
-            if failures > 0
+            if nonzero_exits > 0
                 && let Some(header) = lines.first_mut()
             {
+                let exit_label = if nonzero_exits == 1 {
+                    "nonzero exit"
+                } else {
+                    "nonzero exits"
+                };
                 header
                     .line
-                    .push_span(format!(" · {failures} failed").red().bold());
+                    .push_span(format!(" · {nonzero_exits} {exit_label}").bold());
             }
             lines
                 .into_iter()

codex-rs/tui/src/exec_cell/snapshots/codex_tui__exec_cell__render__tests__truncated_live_output_preview_and_transcript.snap

@@ -26,9 +26,9 @@ expression: "(preview, compact, transcript)"
     ],
     [
         Line::from_iter([
-            Span::from("•").red().bold(),
+            Span::from("•").bold(),
             Span::from(" "),
-            Span::from("Failed (exit 1)").bold(),
+            Span::from("Exited (status 1)").bold(),
             Span::from(" "),
             Span::from("echo").fg(Color::Rgb(137, 180, 250)),
             Span::from(" output").fg(Color::Rgb(205, 214, 244)),