fix: IP-independent pairing key fallback; run commands off the paho thread

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

lgtv_mqtt.py

@@ -18,6 +18,9 @@ import time
 import json
 import logging
 import paho.mqtt.client as mqtt
+from concurrent.futures import ThreadPoolExecutor
+
+worker = ThreadPoolExecutor(max_workers=1)
 
 # --- Config ---
 MQTT_HOST     = "192.168.0.154"   # CT 301 Mosquitto
@@ -110,6 +113,13 @@ def on_connect(client, userdata, flags, rc):
 
 
 def on_message(client, userdata, msg):
+    # Hand off to one worker thread: an `off` can block up to 60s, which starves
+    # paho's keepalive (broker drops us, queued commands are lost). The single
+    # worker keeps commands in order.
+    worker.submit(safe_handle, client, msg)
+
+
+def safe_handle(client, msg):
     # An exception escaping a paho callback kills the network thread while the
     # poll loop keeps the process alive — a silent zombie systemd never restarts.
     try: