fix: recognize real GRUB rescue menuentry

product-source/hololake-platform/guanghu-os/scripts/linux-subcontrol-docker-backend.sh

@@ -70,7 +70,7 @@ verify_machine() {
 }
 
 verify_rescue() {
-  grep -Fq -- "--id '${rescue_slot_id}'" "${grub_cfg}" ||
+  grep -F -- 'menuentry ' "${grub_cfg}" | grep -Fq -- "'${rescue_slot_id}'" ||
     die "independent Linux rescue slot is unavailable"
 }
 

product-source/hololake-platform/guanghu-os/scripts/test-linux-subcontrol-docker-backend.sh

@@ -104,4 +104,10 @@ if "${adapter}" wake jd-linux-on-demand; then
   exit 1
 fi
 
+printf '%s\n' 'set default="gnulinux-simple-9e4550a0-452b-4f28-b5a5-d5364aa450f6"' >"${fixture}/grub.cfg"
+if "${adapter}" preflight jd-linux-on-demand; then
+  echo "a default reference without a rescue menuentry was accepted" >&2
+  exit 1
+fi
+
 echo "GUANGHU_LINUX_SUBCONTROL_DOCKER_BACKEND_OK"