pinwheel: Add greetd module with auto-login

hosts/pinwheel/modules/greetd/default.nix

@@ -0,0 +1,28 @@
+{ pkgs, lib, config, ... }:
+let
+  enabled = config.mod.greetd.enable;
+in
+{
+  options = {
+    mod.greetd = {
+      enable = lib.mkEnableOption "enable greetd module";
+    };
+  };
+
+  config = lib.mkIf enabled {
+    services.greetd = {
+      enable = true;
+
+      settings = let
+        session = {
+          user = "alex";
+          command = "${pkgs.hyprland}/bin/Hyprland";
+        };
+      in
+        {
+          initial_session = session;
+          default_session = session;
+      };
+    };
+  };
+}