decode_event raises on an id triple the XML does not carry, and the XML
is missing at least FlatTrim, so this happens on a real aircraft. The
receive loop already counted and carried on; now something checks it.
The transport is threaded and the session puts an async face on it, so
pings and acks are answered whether or not anyone is awaiting a
coroutine. Telemetry is stored per key with a timestamp, because a drone
that has stopped reporting otherwise reads identically to one repeating
itself.
Encoding goes through protocol/codec lazily, so this lands without
waiting for that stream; the sim carries a small encoder of its own for
the events it sends, which also keeps it from agreeing with the client
about a shared mistake.
Ported from bebop-2's sim.py, retargeted at the vendored XML and with
the identity burst now sent per controller attach rather than once per
process.
rsp2k