moo.shell.tests.test_server.test_data_received_mirrors_capabilities_after_do_gmcp

moo.shell.tests.test_server.test_data_received_mirrors_capabilities_after_do_gmcp()

End-to-end: a client that enables GMCP via DO (without running TTYPE) should see the gmcp capability land in _session_settings immediately, so Celery verbs picking up the next command see GMCP as available.