🏗️ Fix error codes and SEO before 1.2.6 release

[blefnk]

This problem was pointed out by @emontes in the Relivator's Discord (thread). We need to check how the SEO and sharing system will work for external sources, for example, sharing to X/Twitter, Facebook, etc. We need to try fix the functionality of Relivator in the W3 Checker, Meta Sharing Debugger, etc. It's also worth checking if Clerk still needs a Live domain for PageSpeed Insight to work (if it still does, we can't do anything about it, it's up to Clerk to resolve this).