OptionalEmailWhether the authenticated user's identity provider asserted their email as verified
(the OIDC email_verified claim). Three-state by design:
true — the IdP vouched for the email; email-match redemption is allowed.false — the IdP explicitly said the email is UNVERIFIED; the email-match path is
refused (a token still redeems). Without this, any IdP that lets users register an
arbitrary unverified email turns email-match redemption into account takeover.undefined — the transport doesn't know (IdP omits the claim, or an internal caller);
email-match stays allowed unless the claim type's Configuration sets
RequireVerifiedEmail, which demands a positive true.
Options that qualify a redemption attempt with facts only the transport layer knows.