columns(2) must match fields(16)
Differential testing against Trino caught a distributed-scan bug the whole test suite missed: every projected query failed once a scan actually distributed. The first fix restored correctness by disabling projection pushdown. Then a Claude agent on the Fable model found the real bug, one line in the worker's streaming rewrite, and got the speed back: 3.1x overall, 10x on the worst query.
Read