pytest-asyncio builds its loops from the current policy; on win32 that is
the Proactor loop, which zmq.asyncio cannot use, so the engine/serving e2e
hung at the first async socket (30 min, no output, GPU idle) while the
accept CLI -- which installs WindowsSelectorEventLoopPolicy itself --
passed on the same venv. The conftest now installs the same policy and
provides it as pytest-asyncio's event_loop_policy fixture.
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
