What changed
After the second trends release, the history data grew to about 13 MB, and publishing it in one call hit the database's time limit. That publish rolled back cleanly, so the site kept the earlier history, but the new history couldn't go out.
History now uploads in batches of 150 colleges to a staging table. A final step checks that every college arrived, then swaps them all in at once, so visitors never see half a publish.
All 1,893 histories were published this way, then read back and verified.