Enable HEAD request support to fix broken link previews and AI crawling

When you share a Base44 app link on LinkedIn, Slack, or other platforms, the preview often doesn't load, and AI tools like Claude or Perplexity can't read your site's content either.

This is because many crawlers, link previewers, and AI agents send a lightweight "HEAD" request first to check whether a page exists and what kind of content it contains, before fetching the full page. Base44's current infrastructure doesn't support this, so those tools give up before they even try.

The fix is to enable HEAD request handling alongside the existing GET/POST support on custom domains. This would mean:

• Link previews work properly on LinkedIn, Slack, Teams, etc.

• AI tools can discover and read your app's content

• SEO crawlers get cleaner signals about your site

This seems like a low-lift infrastructure change with meaningful upside for anyone using Base44 for public-facing apps.