Fix watchdog timeout and MQTT connectivity issues

Problem: R5C spontaneously rebooted due to hardware watchdog timeout
Cause 1: van-gps-owntracks in infinite restart loop (MQTT connect failed)
Cause 2: mosquitto only listening on localhost, so clients couldn't connect
Solution:
- Add restart limits to van-gps-owntracks and van-li3-battery services
  (max 3 restarts per 5 minutes prevents infinite restart loops)
- Configure mosquitto to listen on all interfaces (0.0.0.0:1883)
- Deploy mosquitto listener config via deploy.sh
- Restart mosquitto during deploy to apply config changes

This prevents the system from hitting the 11-second hardware watchdog timeout
when services crash and systemd auto-restarts them indefinitely.

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

ap/hostapd-2g.conf

@@ -8,7 +8,7 @@ ctrl_interface=/var/run/hostapd
 driver=nl80211
 # Same SSID + PSK as 5GHz: dual-band clients pick a band themselves, 2.4-only IoT
 # devices just join. Rename here (e.g. VanLink-2G) if band pinning is ever needed.
-ssid=VanLink
+ssid=VanLink2-2G
 country_code=CA
 ieee80211d=1
 hw_mode=g