Generate music with a frozen price and one provider submission; Idempotency-Key required

Required. One key per logical request (e.g. ep03-shot042-take1), never reusable: the same key and body answer with the original object and Idempotent-Replayed: true; the same key with a different body is 409 (and so is any reuse once the job's request trace was removed, 180 days after it finished).