Returns the download URLs of a batch's rendered images, one page of jobs at a time, with each job's status and format; downloadUrl is null until that job has rendered. URLs are temporary, so a later call returns fresh ones. Row values and render errors are not included (get_batch_jobs has them), and get_batch is lighter for checking progress. inspect_image can view a downloadUrl. Needs batches:read, renders:read, and creatives:read.