node-core-utils doesn't understand rate-limits

When a rate limit is encountered, the utility currently logs the following message:

✖ Failed to retrieve user info.
username must be a string, received undefined

This could be confusing for collaborators. Ideally, the log should indicate that a rate limit has been reached, such as "Rate limit reached, please try again later." For reference, the GitHub API includes an x-ratelimit-reset header with the specific reset time.

未指定文件或测试。首先定位 node-core-utils 中获取 GitHub 用户信息并处理 API 响应的入口点，然后检查 x-ratelimit-reset 标头是如何暴露的。完成的标准是，速率限制失败时会产生清晰的重试消息，而不是误导性的用户名错误。