add sway and xdg config

sys/modules/default.nix

@@ -15,5 +15,6 @@
     ./bluetooth.nix
     ./net.nix
     ./steam.nix
+    ./xdg.nix
   ];
 }

sys/modules/xdg.nix

@@ -0,0 +1,32 @@
+{
+  config,
+  lib,
+  pkgs,
+  ...
+}:
+with lib; let
+  cfg = config.local.sys.xdg;
+in {
+  options.local.sys.xdg = {
+    enable = mkEnableOption "xdg settings";
+  };
+  config = mkIf cfg.enable {
+    xdg.portal = {
+      enable = true;
+      wlr.enable = true;
+      extraPortals = [pkgs.xdg-desktop-portal-gtk];
+      xdgOpenUsePortal = true;
+      # warning: xdg-desktop-portal 1.17 reworked how portal implementations are loaded, you
+      # should either set `xdg.portal.config` or `xdg.portal.configPackages`
+      # to specify which portal backend to use for the requested interface.
+      #
+      # https://github.com/flatpak/xdg-desktop-portal/blob/1.18.1/doc/portals.conf.rst.in
+      #
+      # If you simply want to keep the behaviour in < 1.17, which uses the first
+      # portal implementation found in lexicographical order, use the following:
+      #
+      # xdg.portal.config.common.default = "*";
+      config.common.default = "*";
+    };
+  };
+}