every nostr client should just generate a random key. you can "log in" by signing that key with your identity key, and then your identity can be a hardware key because you only use it to log in

GitHub

NIP-102: Subkey Attestation by ynniv · Pull Request #1450 · nostr-protocol/nips

This NIP defines a way to separate identity from authentication using hierarchical deterministic (HD) keys. This allows people to use one key pair ...