Yeah, that's why I'm keeping everything client-side. There's no backend. This is hosted on Cloudflare Pages, everything on the backend is static.
Definitely not looking to host any generated images.
On Mobile Safari at least, you can press and hold the image to share. I imagine there's probably an equivalent gesture on Mobile Chrome. I spent considerable time many years ago trying to figure out how to indicate to users that they could do this. ("press and hold to share", with a progress indicator) Results were mixed.
Fortunately, these days if you wanted to make it more obvious you could hook up a regular Share button to navigator.share() API and pass it your image blob.
Fortunately, these days if you wanted to make it more obvious you could hook up a regular Share button to navigator.share() API and pass it your image blob.