feat: extract tuigreet and workstation modules

modules/nixos/workstation.nix

@@ -0,0 +1,32 @@
+{
+  lib,
+  config,
+  pkgs,
+  ...
+}:
+let
+  cfg = config.workstation;
+in
+{
+  options = {
+    workstation = {
+      enable = lib.mkEnableOption "workstation utilities";
+    };
+  };
+
+  config = lib.mkIf cfg.enable {
+    virtualisation.docker = {
+      enable = true;
+      logDriver = "json-file";
+    };
+
+    services.tailscale = {
+      enable = true;
+      useRoutingFeatures = "both";
+    };
+
+    environment.systemPackages = with pkgs; [
+      smartmontools
+    ];
+  };
+}