Describe the bug
There's a mistake in the regex for a bluesky username. Line 18 has this:
https://github.com/TumblThreeApp/TumblThree/blob/master/src/TumblThree/TumblThree.Domain/Models/UrlValidator.cs#L18

But you're allowed to use -; this means that some domain-based handles are not seen as a bluesky profile URL because they contain a dash in them. (Also in theory they're limited to 18 characters, but try as I might I've not found a single page in bluesky that makes mention of the user handle limitations! Best I can find is https://nuelink.com/tools/bluesky-character-counter which will at least show you if the text you enter is a valid user handle)

To Reproduce
Steps to reproduce the behavior:

1. Try add any bsky user handle with a dash in it (eg: https://bsky.app/profile/random-example.bsky.social )
2. The add Blog button is greyed out

Expected behavior
The add blog button not be greyed out

Screenshots
With a dash:

Without the dash:

Desktop (please complete the following information):

• TumblThree version:
• OS: Windows 11 24H2