Declared amounts that cluster just below a threshold

Compares two adjacent bands below each configured threshold — the last 10% before it against the 10% before that. Real amounts do not crowd the final stretch before a line; an excess there is the classic structuring shape. A cap produces the same bunching honestly, so findings are somewhere to look rather than conclusions. Set structuring_threshold_micros on a policy to measure against a line Ratchet does NOT enforce — a reporting limit, an internal review limit — which is usually the line that actually gets hugged.