The companion protocol lists PACKET_CHANNEL_DATA_RECV (0x1B) as an
answer to GET_MESSAGE (0x0A). PR #88 added the CHANNEL_DATA_RECV
event and parser, but get_msg() still waited only for
CONTACT_MSG_RECV, CHANNEL_MSG_RECV, ERROR and NO_MORE_MSGS. When the
next queued message is a channel datagram, get_msg() therefore ignored
the device's answer and returned ERROR (reason "timeout") after
default_timeout, which also stops the auto-fetch loop.
Add CHANNEL_DATA_RECV to the expected events and cover it with a test
that runs a real CHANNEL_DATA_RECV frame through MessageReader and
EventDispatcher.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
