Resend a quote's SCA challenge code

Re-send the one-time code for a realtime-funding quote in PENDING_AUTHORIZATION status whose scaChallenge.factor is SMS_OTP. The existing challenge is reused — no new challenge is issued, and its scaChallenge.expiresAt is not extended; once the challenge is past expiresAt it can no longer be authorized.

Only meaningful for customers in a region where SCA is required (e.g. EU); a 409 is returned otherwise. PASSKEY challenges cannot be re-sent and return 409.

In sandbox, the code is always 123456.