steveej-x13s-rmvbl: init with minimal setup

this configures a standalone USB device that doesn't need configuration
of the firmware's EFI variables.

nix/os/devices/steveej-x13s-rmvbl/configuration.nix

@@ -0,0 +1,66 @@
+{ repoFlake
+, pkgs
+, lib
+, config
+, nodeFlake
+, nodeName
+, localDomainName
+, system
+, ...
+}:
+
+{
+  imports = [
+    repoFlake.inputs.sops-nix.nixosModules.sops
+    nodeFlake.inputs.disko.nixosModules.disko
+    ./disko.nix
+
+    ../../profiles/common/user.nix
+
+    {
+      nix.nixPath = [
+        "nixpkgs=${pkgs.path}"
+      ];
+
+      nix.settings.experimental-features = [
+        "nix-command"
+        "flakes"
+      ];
+
+      nix.settings.max-jobs = lib.mkDefault "auto";
+    }
+
+    {
+      services.openssh.enable = true;
+      services.openssh.settings.PermitRootLogin = "yes";
+      services.openssh.openFirewall = true;
+
+      users.commonUsers = {
+        enable = true;
+        enableNonRoot = true;
+      };
+
+      sops.defaultSopsFile = ../../../../secrets/${nodeName}/secrets.yaml;
+      sops.defaultSopsFormat = "yaml";
+    }
+  ];
+
+  networking = {
+    hostName = nodeName;
+
+    firewall.enable = true;
+
+    useNetworkd = true;
+    networkmanager.enable = false;
+  };
+
+  system.stateVersion = "23.11";
+
+  nixpkgs.config.allowUnfree = true;
+
+  environment.systemPackages = [
+    pkgs.util-linux
+    pkgs.coreutils
+    pkgs.vim
+  ];
+}