Found by a real failure on the Linux verification container: latest-only
coalesces on both the provider's outbox and the managed connector's own
receive-side inbox, so a single ReceiveAsync() call is not guaranteed to
land on the first frame broadcast — on a slower host it landed on sequence 3.
The C# test now also prints CULTMESH_GOLDEN_SEQUENCE, and the harness looks
up the TypeScript peer's logged encoding of that same sequence instead of
hardcoding sent === 1.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>