Handle broken pipes gracefully in plugin list output (#53109)

## Why

Piping `codex plugin list` into a consumer such as `head` can close stdout before the full catalog is written, causing a panic.

## What changed

Write both table and JSON output through a fallible writer and treat broken pipes during writing or flushing as success. Continue propagating other output errors.

## Testing

Add unit tests for write and flush failures in both output formats, plus CLI tests that close stdout early and verify a successful exit without a panic.

GitOrigin-RevId: cc4a64e10ad723d26b6de9e731efdc534dbee492

codex-rs/cli/src/plugin_cmd.rs

@@ -37,6 +37,8 @@ use codex_utils_absolute_path::AbsolutePathBuf;
 use codex_utils_cli::CliConfigOverrides;
 use serde::Serialize;
 use std::collections::HashMap;
+use std::io;
+use std::io::Write;
 use std::path::Path;
 use std::path::PathBuf;
 use std::sync::Arc;
@@ -307,17 +309,49 @@ pub async fn run_plugin_list(
         })
         .collect::<Vec<_>>();
 
+    write_plugin_list(&mut io::stdout().lock(), marketplaces, args)
+}
+
+fn write_plugin_list(
+    writer: &mut impl Write,
+    marketplaces: Vec<PluginListMarketplace>,
+    args: ListPluginsArgs,
+) -> Result<()> {
+    let result = render_plugin_list(writer, marketplaces, args)
+        .and_then(|()| writer.flush().map_err(Into::into));
+    match result {
+        // A consumer such as `head` may finish before the full catalog is written.
+        Err(error)
+            if error
+                .downcast_ref::<io::Error>()
+                .is_some_and(|error| error.kind() == io::ErrorKind::BrokenPipe) =>
+        {
+            Ok(())
+        }
+        Ok(()) => Ok(()),
+        Err(error) => Err(error),
+    }
+}
+
+fn render_plugin_list(
+    writer: &mut impl Write,
+    marketplaces: Vec<PluginListMarketplace>,
+    args: ListPluginsArgs,
+) -> Result<()> {
     if args.json {
         let output = JsonPluginListOutput::from_marketplaces(marketplaces, args.available);
-        println!("{}", serde_json::to_string_pretty(&output)?);
+        writeln!(writer, "{}", serde_json::to_string_pretty(&output)?)?;
         return Ok(());
     }
 
     if marketplaces.is_empty() {
         if let Some(marketplace_name) = args.marketplace_name {
-            println!("No plugins found in marketplace `{marketplace_name}`.");
+            writeln!(
+                writer,
+                "No plugins found in marketplace `{marketplace_name}`."
+            )?;
         } else {
-            println!("No marketplace plugins found.");
+            writeln!(writer, "No marketplace plugins found.")?;
         }
     } else {
         for (index, marketplace) in marketplaces.into_iter().enumerate() {
@@ -376,23 +410,25 @@ pub async fn run_plugin_list(
             }
 
             if index > 0 {
-                println!();
+                writeln!(writer)?;
             }
-            println!("Marketplace `{}`", marketplace.name);
+            writeln!(writer, "Marketplace `{}`", marketplace.name)?;
             if let Some(path) = &marketplace.path {
-                println!("{}", path.display());
+                writeln!(writer, "{}", path.display())?;
             } else {
-                println!("Remote catalog");
+                writeln!(writer, "Remote catalog")?;
             }
-            println!();
-            println!(
+            writeln!(writer)?;
+            writeln!(
+                writer,
                 "{:<plugin_width$}  {:<status_width$}  {:<installed_version_width$}  SOURCE",
                 "PLUGIN", "STATUS", "VERSION"
-            );
+            )?;
             for (plugin, status, installed_version, path) in rows {
-                println!(
+                writeln!(
+                    writer,
                     "{plugin:<plugin_width$}  {status:<status_width$}  {installed_version:<installed_version_width$}  {path}"
-                );
+                )?;
             }
         }
     }
@@ -1090,3 +1126,7 @@ fn path_ends_with(path: &Path, suffix: &[&str]) -> bool {
             .collect::<Vec<_>>(),
     )
 }
+
+#[cfg(test)]
+#[path = "plugin_cmd_tests.rs"]
+mod tests;