Get job label hits

Retrieves label occurrences for a job, projected to label, modality, score, and timed fields (start_ms/end_ms and their timecodes). Video frame hits are point-in-time (start only); audio chunk hits are ranged when end_ms is set. Set the optional job_result_id to scope the response to a single result of the job. Hits are paged in a stable order: results in the order they were recorded, and each result's hits in the order the evaluation recorded them (start time ascending for video). Omitting page_size uses the default of 1000. The maximum page_size is 1000. Negative page_size is rejected. When more hits remain, next_page_token is set; pass it as page_token with the same job_uuid and job_result_id to fetch the next page. An incomplete job returns its status with no labels and no next_page_token. Available to policy-first and label-first accounts; works on any job in the account, including jobs from POST /v1/labels/evaluate.