planted-truth — the pipeline runs on synthetic truth first

A pipeline that has only ever seen real data has never been tested, because nobody knew what the right answer was. The only inputs whose correct output is known are the ones you construct. Construct them, run them, and do it before real data is touched.

Real data cannot grade a pipeline. Whatever comes out looks like a finding: a slope, an evidence ratio, a list of anomalies, an empty list of anomalies. If the pipeline drops half its input on a parsing error, the output is smaller and still looks like a finding. If a sign convention is inverted, the conclusion reverses and still looks like a finding. The one situation in which output can be graded is when the answer was written down first — a plant: data generated from known parameters, fed through the full analysis, with recovery demanded to the accuracy the real analysis will claim.