Caller-supplied idempotency key (from the API Idempotency-Key
header). Threaded into productQuoteService.quote() (dedupes the
pinned engine quote) and depositQuoteService.create() (dedupes the
deposit quote). Optional — internal callers don't supply one.
Caller-supplied idempotency key (from the API
Idempotency-Keyheader). Threaded intoproductQuoteService.quote()(dedupes the pinned engine quote) anddepositQuoteService.create()(dedupes the deposit quote). Optional — internal callers don't supply one.