Returns the stored KYB submission, its lifecycle status, and the current beneficial owners. A case created via POST /ukyb but never submitted still returns 200 — the pack exists and you are entitled to read it — with status: "PENDING_SUBMISSION" and both timestamps null. This endpoint is the pull counterpart to the kyb_status_change webhook: use it to learn the outcome of a case before the webhook ships, or to reconcile state after a missed delivery.