failover: fix Starlink interface + template config.json from deploy.conf

STARLINK_IFACE pointed at the wrong device after the USB hub swap (was
accidentally set to the 5GHz AP dongle's interface). failover/config.json
also hardcoded the old interface name instead of being templated like the
other configs, so deploy.conf changes never reached it — switched it to
@STARLINK_IFACE@ and deploy.sh now renders it.

deploy.conf

@@ -20,7 +20,8 @@ WIFI_2G_IFACE=wlx3c3332002066
 LAN_USB_IFACE=enx00e04c331140
 
 # Starlink dish uplink, USB-attached gigabit adapter (RTL8153-family)
-STARLINK_IFACE=enxd8ec5eeb3512
+#STARLINK_IFACE=enxd8ec5eeb3512	# White Belkin dongle
+STARLINK_IFACE=enx6c1ff7d210a5  # UGreen 8-port hub's built-in Ethernet (ASIX AX88179B)
 
 # Cellular modem USB vendor ID (Quectel EC25-AF)
 MODEM_USB_VENDOR=2c7c

deploy.sh

@@ -127,7 +127,7 @@ dpkg -s zerotier-systemd-manager >/dev/null 2>&1 \
 
 echo "== failover =="
 install -D -m0755 failover/van-failover         /usr/local/sbin/van-failover
-install -D -m0644 failover/config.json          /etc/van-failover/config.json
+install_rendered failover/config.json           /etc/van-failover/config.json
 install -D -m0644 failover/van-failover.service /etc/systemd/system/van-failover.service
 install -D -m0755 failover/50-disable-eee       /etc/NetworkManager/dispatcher.d/50-disable-eee
 install -D -m0644 failover/99-van-arp.conf      /etc/sysctl.d/99-van-arp.conf

failover/config.json

@@ -10,7 +10,7 @@
   ],
   "wans": [
     { "name": "wifi",     "device": "wlan0",           "metric": 100 },
-    { "name": "starlink", "device": "enxd8ec5eeb3512", "metric": 200 },
+    { "name": "starlink", "device": "@STARLINK_IFACE@", "metric": 200 },
     { "name": "cellular", "connection": "Koodo",       "metric": 300 }
   ]
 }