Previously the ws_bridge send loop blocked forever on queue.get(),
never learning the client left. When the server service stopped,
uvicorn waited for open WebSocket tasks until systemd SIGKILLed
after TimeoutStopSec=90s. Now each iteration races recv+send; a
completed receive means the client disconnected => break the loop.
Every other built-in tool is imported here specifically to fire its
@ToolRegistry.register() decorator at package-load time; these two
were missing, so their test_registered tests only passed when some
unrelated test (via agent_manager_routes.py, channels_cmd.py, or
deep_research_setup_cmd.py) happened to import the module first in
the same process. Under pytest-xdist that's worker-distribution
dependent, so adding an unrelated test file could flip either test
from pass to fail.
Ari