fix(node): clarify wireless enrollment and restore active K1 after upgrade

apps/node-agent/packaging/postinst

@@ -15,6 +15,14 @@ case "$1" in
       systemctl enable mission-core-node.service
       systemctl restart mission-core-node.service
       systemctl try-restart mission-core-realsense.service
+      if [ -f /run/mission-core-node-k1-upgrade-active ]; then
+        # A jointly upgraded plugin starts itself after its own configuration.
+        # Restore it here only when that package is already configured.
+        if [ "$(dpkg-query -W -f='${Status}' mission-core-xgrids-k1 2>/dev/null || true)" = "install ok installed" ]; then
+          systemctl start mission-core-k1.service
+        fi
+        rm -f /run/mission-core-node-k1-upgrade-active
+      fi
     fi
     ;;
 esac