feat(unitree_g1): make onboard state PUB toggleable + lower default rate

Lower observation.state publish rate to 30 Hz and allow disabling it with
--state-fps <=0, so the onboard runner can reproduce the plain-teleop setup
(no state thread) for A/B isolation of camera-stability issues.

Co-authored-by: Cursor <cursoragent@cursor.com>

src/lerobot/robots/unitree_g1/run_g1_onboard.py

@@ -74,7 +74,12 @@ def main() -> None:
         default=STATE_PORT,
         help="ZMQ PUB port for observation.state feedback (29 joint .q) to the inference client",
     )
-    p.add_argument("--state-fps", type=float, default=60.0, help="observation.state publish rate (Hz)")
+    p.add_argument(
+        "--state-fps",
+        type=float,
+        default=30.0,
+        help="observation.state publish rate (Hz); set <=0 to disable the state PUB entirely",
+    )
     p.add_argument(
         "--gravity-compensation",
         action="store_true",
@@ -152,22 +157,26 @@ def main() -> None:
     sock.bind(f"tcp://0.0.0.0:{args.action_port}")
     logger.info("Onboard controller live. Waiting for laptop actions on :%d ...", args.action_port)
 
+    stop = threading.Event()
+    signal.signal(signal.SIGINT, lambda *_: stop.set())
+    signal.signal(signal.SIGTERM, lambda *_: stop.set())
+
     # Proprioception feedback: publish observation.state (29 joint .q) so the
     # laptop-side inference client can feed it to the policy. DDS stays local to
     # the robot; only this compact JSON state crosses the network (like the
-    # camera/action ZMQ channels).
+    # camera/action ZMQ channels). get_observation() here reads only DDS lowstate
+    # (the robot is built with cameras={}), so it never touches the USB cameras.
+    # Disable with --state-fps <=0 (e.g. to reproduce the plain-teleop setup).
+    state_sock = None
+    if args.state_fps > 0:
         state_sock = ctx.socket(zmq.PUB)
         state_sock.setsockopt(zmq.SNDHWM, 2)
         state_sock.setsockopt(zmq.LINGER, 0)
         state_sock.bind(f"tcp://0.0.0.0:{args.state_port}")
         logger.info("Publishing observation.state on :%d at %.0f Hz", args.state_port, args.state_fps)
 
-    stop = threading.Event()
-    signal.signal(signal.SIGINT, lambda *_: stop.set())
-    signal.signal(signal.SIGTERM, lambda *_: stop.set())
-
         def publish_state() -> None:
-        period = 1.0 / args.state_fps if args.state_fps > 0 else 0.0
+            period = 1.0 / args.state_fps
             joint_names = [j.name for j in G1_29_JointIndex]
             while not stop.is_set():
                 t0 = time.time()
@@ -178,10 +187,11 @@ def main() -> None:
                         state_sock.send_json(state, zmq.NOBLOCK)
                     except zmq.Again:
                         pass
-            if period:
                 time.sleep(max(0.0, period - (time.time() - t0)))
 
         threading.Thread(target=publish_state, daemon=True).start()
+    else:
+        logger.info("observation.state PUB disabled (--state-fps<=0); inference client will get no proprio")
 
     n = 0
     try:
@@ -234,6 +244,7 @@ def main() -> None:
     finally:
         logger.info("Shutting down onboard controller...")
         stop.set()
+        if state_sock is not None:
             try:
                 state_sock.close(linger=0)
             except Exception as e:  # noqa: BLE001