create shared niri config, refactor generic feature modules

modules/features/hardware/steam-controller.nix

@@ -5,6 +5,8 @@
 
   flake.nixosModules.gaming = { pkgs, config, lib, ... }: {
     config = lib.mkIf (config.features.hardware.steam-controller.enable) {
+      hardware.steam-hardware.enable = lib.mkForce true; # most likely enabled somewhere else but should be enforced here regardless
+
       home-manager.users.${config.info.userName} = lib.mkIf (config.features.nixos.home-manager.enable) {
         features.hardware.steam-controller.enable = lib.mkDefault true;
       };
@@ -14,8 +16,8 @@
   flake.homeModules.gaming = { pkgs, config, lib, inputs, ... }: {
     config = let
       pkgsCross = import inputs.nixpkgs {
-        localSystem = "x86_64-linux";
-        hostSystem = "x86_64-linux";
+        localSystem = pkgs.stdenv.hostPlatform.system;
+        hostSystem = pkgs.stdenv.hostPlatform.system;
         crossSystem = "i686-linux";
       };
       steam-modified-desktop-file = pkgs.runCommand "modifySteamDesktopFile" {} ''