feat: add device usage check before preparing ZFS datasets

prepare-zfs-datasets.sh

@@ -9,6 +9,12 @@ echo ""
 echo "Enter the device to use for the ZFS pool (e.g., /dev/sdb):"
 read device
 
+# Confirm the device is not in use
+if mount | grep "$device"; then
+  echo "Error: $device is already mounted. Exiting..."
+  exit 1
+fi
+
 # Ask for confirmation, since this script will destroy all data on the device
 echo "This script will destroy all data on $device. Are you sure you want to continue? (y/n)"
 read confirm