Disclaimer, I don't have idea what I'm talking about. I mean somehow use cryptography to derive passwords (into a specific encoding that satisfies typical password requirements) such that the experience is "like" LNURL-Auth In there, secret = hmac(private key, site.com) ; perhaps using those per-site secrets and derive from there.

lnurl-auth explained

Any derivation metadata along with username etc, could more safely go to relays (still encrypted) as there would be no passwords. Logging in somewhere would require hmac signing with the nsec. Feel free to discard if this totally stupid lol