perf: speed up zfs-diff

hosts/nixos-laptop/default.nix

@@ -21,9 +21,20 @@
       personal.enable = true;
       # webis.enable = true;
     };
-    shell.aliases.zfs-diff = "sudo zfs diff zroot/encrypted/root@blank | parallel --pipe cut -f2 | parallel 'test -e /persist/{} || echo {}' | ${lib.getExe pkgs.tree} --fromfile .";
   };
 
+  environment.systemPackages = [
+    (
+      pkgs.writeShellApplication {
+        name = "zfs-diff";
+        runtimeInputs = with pkgs; [ zfs coreutils parallel tree ];
+        text = ''
+          sudo zfs diff zroot/encrypted/root@blank | cut -f2 | parallel 'test -d /persist/{} || echo {}' | tree --fromfile .
+        '';
+      }
+    )
+  ];
+
   home-manager.users.moritz.home.packages = with pkgs; [
     # jetbrains.idea-ultimate
   ];