fix: survive command exceptions; TV DHCP-reserved so pairing key stays valid

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

lgtv_mqtt.py

@@ -110,6 +110,15 @@ def on_connect(client, userdata, flags, rc):
 
 
 def on_message(client, userdata, 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:
+        handle_command(client, msg)
+    except Exception:
+        log.exception("command handling failed")
+
+
+def handle_command(client, msg):
     command = msg.payload.decode().strip().upper()
     log.info(f"Received command: {command}")