Log in with passkey: error handling

[dcposch]

Summary

Currently, if a user tries to log in with passkey & selects the wrong passkey:

• The transaction fails ( with AA24: signature error)
• The UI shows an infinite spinner

Proposed fix

• After user selects a passkey, verify that the pubkey is present on the account before submitting a login tx. This lets us show a "wrong passkey" error immediately.
• If login tx reverts for any reason, show a friendly error with a retry button.