Fixed
- Apple IDs with FIDO/WebAuthn security keys fail fast with a clear error. Accounts with a YubiKey or other hardware security key registered could sign in through SRP + 2FA, then hit an opaque CloudKit
HTTP 401 AUTHENTICATION_FAILED "no auth method found"on the first API call and loop through re-auth untilAUTH_ERROR_THRESHOLDstopped the sync. SRP now inspects the/signin/complete409 body forfsaChallenge/keyNamesand bails withAuthError::FidoNotSupported { key_names }before prompting for a 2FA code. The message names the registered keys and points to Settings > Apple ID & iCloud > Sign-In & Security > Security Keys. As a defense-in-depth,HttpStatusErrornow preserves a truncated copy of the CloudKit error body, and a 401 carrying "no auth method found" logs a WARN with the security-key hint and a link to the tracking issue. (#221)
Full changelog: CHANGELOG.md