Solokey authentication

Solokeys are physical hardware authentication (U2F / FIDO2) devices, that you plug into a USB port, which stores a secret key that can be used as primary or secondary authentication factors (2FA), with websites (Webauthn), and machines (sudo and SSH).

There are two versions of solokey now, v1 and v2, and they require separate toolchains. The instructions diverge here depending on which hardware revision you have.