Sudo autofill only read host.password and never resolved a host's reference
to a Keychain identity (host.identityId). When the account password lived in
a referenced identity, the autofill got nothing — while SSH login worked
because it goes through resolveHostAuth, which resolves the identity.
Add domain resolveHostAutofillPassword (same resolveHostAuth resolution:
identity.password ?? host.password, honoring savePassword and dropping
undecryptable placeholders) and use it as the terminal autofill password
source. Login and autofill now share one resolution path.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>