One tenth of an inch is worth a pound on a bulky parcel, and the round-up rule cuts in the carrier's favour. The audit applies the round-up to your declared dimensions and shows both the rounded and the truncated weight, so you can see whether the carrier rounded the way its own tariff requires.
Paste or upload the shipment records you handed over and the carrier's invoice lines. The audit runs in this page — the same deterministic engine the agent tools call.
The examples are synthetic worked cases (the same fixtures the build gate asserts against). Your own files are audited in the browser: no upload, no LLM, no third-party call.