Add phone hotspot uplink

Prefer a configured phone hotspot for outbound synchronization, preserve secure write-only credentials, and recover through home WiFi or the local Pi hotspot.

Co-authored-by: Copilot <[email protected]>

deploy/90-yaris-uplink

@@ -0,0 +1,9 @@
+#!/bin/sh
+
+[ "$1" = "wlan0" ] || exit 0
+
+case "$2" in
+    up|down|connectivity-change|dhcp4-change)
+        /usr/local/bin/yaris-uplink record >/dev/null 2>&1 || true
+        ;;
+esac