Add a new theme and tamper with some files

modules/system/devices/boot/lanzaboote/default.nix

@@ -1,4 +1,4 @@
-{ lanzaboote, ... }:
+{ lanzaboote, pkgs, ... }:
 {
   imports = [
     lanzaboote.nixosModules.lanzaboote
@@ -8,4 +8,8 @@
     enable = true;
     pkiBundle = "/etc/secureboot";
   };
+
+  environment.systemPackages = with pkgs; [
+    sbctl
+  ];
 }