Which messages this client speaks. A claim to stand where a gateway
stood is a claim about messages rather than about method names, so
this is taken from the dispatch tables and the message builders
themselves, and CI regenerates it and fails if it has drifted.
Test code is excluded: a fixture that builds a message is not this
client sending one.
What this does not establish: a type absent here is one this client
neither sends nor handles, which is not the same as one the venue never
sends. Settling that needs a record of everything the venue can send.
How it is read: the four connections' dispatch tables, the subtypes
written beside the tag that carries them under either of its names, and
the constants named as sub-protocols. A subtype reaching the wire by
some other shape would be missing from this page, and one has been:
the calendar's, passed as a named constant rather than spelled out,
which is why constants are read too.