Add codex app macOS launcher (#10418)

- Add `codex app <path>` to launch the Codex Desktop app.
- On macOS, auto-downloads the DMG if missing; non-macOS prints a link
to chatgpt.com/codex.

codex-rs/cli/src/main.rs

@@ -31,6 +31,10 @@ use std::io::IsTerminal;
 use std::path::PathBuf;
 use supports_color::Stream;
 
+#[cfg(target_os = "macos")]
+mod app_cmd;
+#[cfg(target_os = "macos")]
+mod desktop_app;
 mod mcp_cmd;
 #[cfg(not(windows))]
 mod wsl_paths;
@@ -98,6 +102,10 @@ enum Subcommand {
     /// [experimental] Run the app server or related tooling.
     AppServer(AppServerCommand),
 
+    /// Launch the Codex desktop app (downloads the macOS installer if missing).
+    #[cfg(target_os = "macos")]
+    App(app_cmd::AppCommand),
+
     /// Generate shell completion scripts.
     Completion(CompletionCommand),
 
@@ -564,6 +572,10 @@ async fn cli_main(codex_linux_sandbox_exe: Option<PathBuf>) -> anyhow::Result<()
                 )?;
             }
         },
+        #[cfg(target_os = "macos")]
+        Some(Subcommand::App(app_cli)) => {
+            app_cmd::run_app(app_cli).await?;
+        }
         Some(Subcommand::Resume(ResumeCommand {
             session_id,
             last,