Create table rows

Append up to 1000 empty rows to the table (one by default) and request a SINGLE row-added recompute run scoped to all of them. The row cap is enforced atomically over the whole batch, so the append is all-or-nothing. Passing after_record_id or before_record_id instead inserts exactly one row directly below or above that row, touching no other row's position. The run appears on the next active-runs poll; the response never carries a run ID, and a table with no formula columns discards the request at plan time.