Seven Failure Scenarios Test a Verifiable Supply-Chain Ledger's Resilience

The third experiment in a verifiable supply-chain series tests how a state-transition primitive behaves under violations rather than only on the happy path. An 18-test scenario matrix runs a shipment through offer, handoff, settlement and verification on an in-memory ledger, covering seven scenarios from undeclared telemetry to double settlement. Each scenario asserts that advisory flags fire only for the violation they name and that settlement stays exactly-once under concurrency. Assertions check both the write payload and the replayed read model, so the tests confirm the projection and not just that calls succeeded. The suite was extended after an adversarial AI audit found six high-severity gaps, each now covered by a dedicated regression test.