Bug: Custom rules cannot be added for domains without an extension.

The UI currently restricts users from blocking domains like "xn--*" by stating it's not a valid domain. However, when using the API or through a network monitor with a fetch request, it's possible to bypass this limitation.

Although the blocking functionality works for punycode domains, the UI fails to support this feature, preventing users from blocking domains without extensions directly.

It would be nice if users could add domains without an extension through the UI.😁