Update header from Working once batched commands are done (#2249)

Update commands from Working to Complete or Failed after they're done

before:
<img width="725" height="332" alt="image"
src="https://github.com/user-attachments/assets/fb93d21f-5c4a-42bc-a154-14f4fe99d5f9"
/>

after:
<img width="464" height="65" alt="image"
src="https://github.com/user-attachments/assets/15ec7c3b-355f-473e-9a8e-eab359ec5f0d"
/>

codex-rs/tui/src/history_cell.rs

@@ -342,7 +342,11 @@ impl HistoryCell {
         parsed_commands: &[ParsedCommand],
         output: Option<&CommandOutput>,
     ) -> Vec<Line<'static>> {
-        let mut lines: Vec<Line> = vec![Line::from("⚙︎ Working")];
+        let mut lines: Vec<Line> = vec![match output {
+            None => Line::from("⚙︎ Working".magenta().bold()),
+            Some(o) if o.exit_code == 0 => Line::from("✓ Completed".green().bold()),
+            Some(o) => Line::from(format!("✗ Failed (exit {})", o.exit_code).red().bold()),
+        }];
 
         for (i, parsed) in parsed_commands.iter().enumerate() {
             let text = match parsed {