The complete derivation chain for a compiled statement.

Everything here is already inside the signed statement; what this adds is order and attribution. Steps run from the polygon through grid addressing, signed measurement, algorithm evaluation against pinned registries, aggregation, the consignment verdict, citations, the independent guard verdict, the engine signature and the transparency-log anchor. Three keys sign parts of the chain and they are not interchangeable — signing_parties keeps them separate. A stage whose evidence is absent is emitted as absent WITH a reason rather than omitted, and not_established states what the chain does not show.