Extend the fake Nexus/Praxis/Hexis harness with request header and query
capture, a malformed-body lever, a response delay lever, and a request
counter, then add a degraded-mode suite on top of it: independent outages,
malformed and drifted contracts, cancellation, execution failure vs
transport failure, ambiguous targets, no autonomous Praxis to Hexis
chaining, confirmation for mutating capabilities, and recovery without a
restart.