Amethyst is giving share links hosted by snort.social - is this standard for Nostr across all clients? That site is definitely not previewing on Twitter, so it could really benefit from this.
All In One SEO for WordPress has the code for all preview formats.
https://aioseo.com/ - it's php, so easily lifted.
Discussion
Now we have to ask: is how Nostr serving URLs for sharing notes on the Web a weakness in its decentralization architecture?