Moving the dedup flush and thread lookup from asyncio.to_thread onto the
adapter-owned pool fixed the torn-down default executor, but to_thread also
copies the caller's contextvars and run_in_executor does not. A multiplexed
profile's HERMES_HOME override and secret scope are contextvars, so those
workers silently ran under the launch profile. _run_blocking now runs the call
through contextvars.copy_context().run, matching to_thread semantics.
Review finding: _run_blocking lost the profile HERMES_HOME override / secret scope on the worker.
teknium1
2298dc8122