TODO: implement basic auth and user switching functionality.

[Kaikei-e]

Until now, I had only considered this for personal use. However, if it is to be a comprehensive product quality application, it is essential to have a feature for managing RSS feeds for each user. Therefore, I plan to implement user authentication (since I only anticipate usage on local machines at this point, I'll use Basic authentication for convenience) and manage feeds for each user. I also plan to control and manage situations where multiple users have registered the same RSS feed, including the count of favorites and registrations.