PlayerData, CultMeshSimulationFact, the Networking interop peer's
CultNetInteropNote, the cultnet-py benchmark item and the Caching test
documents lacked [MessagePackObject]. Only the generated codec could
serialize them; MessagePackSerializer refuses such types. Non-public test
documents take [MessagePackObject(AllowPrivate = true)], as consumer
internal documents already do, and ConditionalCommitTests.Slow marks its
private backing fields [IgnoreMember].
Same [Key]s, so payloads are unchanged: a pre/post probe over the
Networking assembly and both interop peers showed identical schema id,
content hash and payload bytes for all 9 documents, PlayerData equal once
its Guid.NewGuid() default id is masked.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>