Queue a batch of horses for paced form collection

Cost: free to submit. 3 credits per horse when it is delivered.

Hand us a list of horses and we collect their Racing Australia form at a pace RA tolerates, then hold it for you. This is the supported way to backfill a model: looping /v1/racing/horses/form yourself will trip RA's bot protection long before a few thousand horses, and the 503s that follow are shared with every other customer.

Names resolve the same way they do on the form endpoint — against acceptances (about three days ahead) and every archived result runner — and so do the pe: horse_refs published on results, the live board, the archives and /v1/racing/horses/runs, which is the spelling to submit if you are working from those. A horse we have never seen comes straight back in not_found rather than being queued, and costs nothing. ambiguous is always empty: a name resolves to one horse (several Racing Australia codes under one name are the same horse's codes from different days, not several horses).

Horses we already hold a fresh copy of skip the queue and are ready at once — matched on the HORSE, so a page collected under any of its codes counts and no read of Racing Australia is spent re-fetching it. A horse already queued for you is not queued twice.

Poll GET /v1/racing/horses/backfill/{job_id} for progress and collect from /results as rows complete — you do not have to wait for the whole batch.