fix: endpoints don't create sockets

ref: N25B-217

src/control_backend/api/v1/endpoints/command.py

@@ -17,8 +17,7 @@ async def receive_command(command: SpeechCommand, request: Request):
     # Validate and retrieve data.
     SpeechCommand.model_validate(command)
     topic = b"command"
-    pub_socket = Context.instance().socket(zmq.PUB)
-    pub_socket.connect(settings.zmq_settings.internal_pub_address)
+    pub_socket = request.app.state.endpoints_pub_socket
     await pub_socket.send_multipart([topic, command.model_dump_json().encode()])
 
     return {"status": "Command received"}