Update configuration.nix

configuration.nix

@@ -218,6 +218,9 @@
 
     serviceConfig = {
       Type = "simple";
+      Restart = "always";
+      RestartSec = "1";
+
       ExecStart = pkgs.writeShellScript "watch-root-device" ''
         set -e
 
@@ -227,10 +230,14 @@
         SLEEP=${pkgs.coreutils}/bin/sleep
         SYSTEMCTL=${pkgs.systemd}/bin/systemctl
 
-        ROOT_SRC="$($FINDMNT -n -o SOURCE / || true)"
-        [ -z "$ROOT_SRC" ] && exit 0
+        # Wait until root is visible
+        while true; do
+          ROOT_SRC="$($FINDMNT -n -o SOURCE / 2>/dev/null || true)"
+          [ -n "$ROOT_SRC" ] && break
+          $SLEEP 1
+        done
 
-        # Resolve to top-level disk exactly once
+        # Resolve to top-level block device
         PARENT="$($LSBLK -ndo PKNAME "$ROOT_SRC" 2>/dev/null || true)"
         if [ -n "$PARENT" ]; then
           ROOT_DEV="/dev/$PARENT"
@@ -240,16 +247,18 @@
 
         DEV_NAME="$($BASENAME "$ROOT_DEV")"
 
-        # Sanity check: ensure device exists before watching
-        [ ! -e "/sys/class/block/$DEV_NAME" ] && exit 0
-
-        while [ -e "/sys/class/block/$DEV_NAME" ]; do
+        # Wait until sysfs entry exists
+        while [ ! -e "/sys/class/block/$DEV_NAME" ]; do
           $SLEEP 1
         done
 
+        # Watch until device disappears
+        while [ -e "/sys/class/block/$DEV_NAME" ]; do
+          $SLEEP 0.5
+        done
+
         $SYSTEMCTL poweroff
       '';
-      Restart = "no";
     };
   };