Add a role for loading esims onto standalone sim cards.

nix/configuration/roles/esim/default.nix

@@ -0,0 +1,33 @@
+{
+  config,
+  lib,
+  pkgs,
+  ...
+}:
+
+{
+  imports = [ ];
+
+  options.me = {
+    esim.enable = lib.mkOption {
+      type = lib.types.bool;
+      default = false;
+      example = true;
+      description = "Whether we want to install esim.";
+    };
+  };
+
+  config = lib.mkIf (config.me.esim.enable && config.me.graphical) {
+    environment.systemPackages = with pkgs; [
+      easylpac
+      zbar # To decode qrcodes via `zbarimg <file>`
+    ];
+
+    nixpkgs.overlays = [
+      (final: prev: {
+        easylpac = (final.callPackage ./package/easylpac/package.nix { });
+      })
+    ];
+
+  };
+}