Function
send-batch
Produce many records to one topic.
The result is positional: entry N is the delivery outcome for record N. Records are enqueued before their delivery reports are awaited so the provider can batch them. A record rejected before enqueue appears as an error in its position; it does not fail unrelated entries.
send-batch: async func(topic: string, records: list<produce-record>) -> result<list<result<produce-ack, error>>, error>;