Expand description
Test fixture: a hand-authored sliver of UCI 2.5, not the message catalog.
Covers Ping, PositionReport (oa-gateway-testing fixtures), PolySample ($type),
and MA_RxDataPayload / MA_TxDataPayloadCommand enough to convert wrap shells.
This exists so the conversion tests can run without a local copy of the
standard. Nothing in the gateway uses it: adapters are handed a schema
compiled from the published XSD by crate::xsd::compile. Reach for this
only in tests, and prefer a small inline schema when the shape is what
matters.