Make GPS, Bluetooth, and modem packages required

Move python3-gps, python3-bleak to REQUIRED_PACKAGES (needed for van-li3-battery,
van-gps-owntracks). Add modemmanager to REQUIRED_PACKAGES (provides mmcli for
van-sms-* services).

Deploy will now fail if these packages are missing, preventing silent failures
when GPS or SMS services are needed.
Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

deploy.sh

@@ -54,6 +54,9 @@ REQUIRED_PACKAGES=(
     nftables
     dnsmasq
     systemd-resolved
+    python3-gps
+    python3-bleak
+    modemmanager
 )
 OPTIONAL_PACKAGES=(
     rsync
@@ -61,8 +64,6 @@ OPTIONAL_PACKAGES=(
     gpsd
     gpsd-clients
     python3-paho-mqtt
-    python3-gps
-    python3-bleak
     mobile-broadband-provider-info
     zerotier-one
 )