I recently fixed a bug in [this PR](https://github.com/openai/codex/pull/6285) that prevented Ctrl+C from dismissing the login menu in the TUI and leaving the user unauthed. A [user pointed out](https://github.com/openai/codex/issues/6418) that this makes Ctrl+C can no longer be used to exit the app. This PR changes the behavior so we exit the app rather than ignoring the Ctrl+C.