A speed claim a reader cannot reproduce is a screenshot. This harness
installs manifoldbt from PyPI like any user would, generates its own data,
and gates every timing behind a parity check: a workload where the two
engines disagree publishes nothing and fails the run.
It lives here rather than in the engine repository because it benchmarks the
published wheel, not the source. Anyone can fork this repository and press
"Run workflow" to get the same table on their own runner.
The workflow runs on demand, weekly, and on every published release, so a
version that gets slower says so in public.
