Fix anonymous author microdata for Google Rich Results

[rxchun]

Summary

Adds an empty <meta itemprop="url" content="" /> for anonymous post authors to satisfy Google structured data requirements, without affecting registered users.

Details

• When $microdata is true and the post author is anonymous, the generated HTML now wraps the author name in:

<span itemprop="author" itemscope itemtype="https://schema.org/Person">
  <span itemprop="name">anonymous</span>
  <meta itemprop="url" content="" />
</span>

• This prevents Google Rich Results warnings about missing url.
• Registered users (with <a> links) are unaffected.
• The patch does not change any IP display or other functionality.

Testing

• Verified anonymous posts render the proper <meta itemprop="url">.
• Verified registered users continue to render their existing linked name correctly.

Issue addressed

Google structured data requires an author/url field. Anonymous authors previously triggered warnings in Rich Results testing tools.

[rxchun]

The URL actually needs to contain content, as reported by the webmaster who found this issue.

Since there isn't a default fallback user to reference anonymous content, or attribute stray content like StackOverflow does with the user @community, the best solution here is to set the link to the Users page. This ensures that SEO has a valid page to reference without leading to a 404 error.

Using mysite.com/users/anonymous could be problematic since it might either:

• Point to a real user with the username "anonymous," or
• Result in a 404 error if such a user doesn’t exist.

By pointing to the general Users page (mysite.com/users/), we avoid these issues and maintain valid structured data without exposing sensitive information or creating misleading URLs.