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.conf.bak

@@ -0,0 +1,31 @@
+interface=@WIFI_5G_IFACE@
+# Put the AP into br0 so Wi-Fi and the wired LAN port share one 10.42.0.0/24 segment.
+# hostapd adds the wlan to the bridge after setting AP mode; the bridge itself + its
+# wired member + the gateway IP are defined under /etc/systemd/network (2x-van-br0/lan).
+bridge=br0
+# Control socket so van-ap-watchdog (and hostapd_cli) can read the AP's real state
+# (state=ENABLED means it's actually beaconing) — used to detect a wedged radio that
+# stays "running" but stops serving after a USB glitch.
+ctrl_interface=/var/run/hostapd
+driver=nl80211
+ssid=VanLink2
+country_code=CA
+ieee80211d=1
+ieee80211h=0
+hw_mode=a
+channel=149
+wmm_enabled=1
+ieee80211n=1
+ht_capab=[HT40+][SHORT-GI-20][SHORT-GI-40]
+ieee80211ac=1
+vht_oper_chwidth=1
+vht_oper_centr_freq_seg0_idx=155
+vht_capab=[RXLDPC][SHORT-GI-80][SU-BEAMFORMEE]
+ieee80211ax=1
+he_oper_chwidth=1
+he_oper_centr_freq_seg0_idx=155
+auth_algs=1
+wpa=2
+wpa_passphrase=1foot11foot11
+wpa_key_mgmt=WPA-PSK
+rsn_pairwise=CCMP