Is your feature request related to a problem? Please describe.
Support conditional / autofill Webauthn flows

Describe the solution you'd like
Built-in stages to build a conditional / autofill Webauthn flow, as described by W3C, Yubico, and Google.

Describe alternatives you've considered
This is a new style of authentication flow promoted by Apple, Google, Microsoft, and others under the "passkey" consumer umbrella.