To verify a Mastodon account, one has to add the code below to the home page of a website. The code can be easily added to an Obsidian note that is published via Obsidian Publish.
<a rel="me" href="https://mastodon.social/@vladcampos"></a>
However, because of the way Obsidian Publish builds the website pages, that code doesn’t show up on the published page, therefore Mastodon’s validation system can’t see it.
As for author attributions on articles, one has to add the code below to the home page of a website.
<meta name="fediverse:creator" content="@[email protected]">
Just like mentioned above, it is possible to do it on a note, but, again, it is not visible on the website and Mastodon cannot use this to give attribution to authors.
Although the codes above can be in any part of the home page, probably a more broad solution that would cover other setting beyond Mastodon, would be to have some sort of head.html note, similar to publish.css where we could add codes like the above inside the <head></head> tags.