Add steam

Signed-off-by: Nikolaos Karaolidis <nick@karaolidis.com>

hosts/common/user/configs/gui/gaming/default.nix

@@ -0,0 +1,37 @@
+{
+  user ? throw "user argument is required",
+  home ? throw "home argument is required",
+}:
+{ pkgs, ... }:
+{
+  environment.persistence."/persist" = {
+    "${home}/.steam" = { };
+    "${home}/.local/share/Steam" = { };
+  };
+
+  programs = {
+    steam = {
+      enable = true;
+      localNetworkGameTransfers.openFirewall = true;
+      extest.enable = true;
+      protontricks.enable = true;
+    };
+
+    gamescope = {
+      enable = true;
+      args = [
+        "--rt"
+        "-f"
+      ];
+    };
+
+    gamemode.enable = true;
+  };
+
+  home-manager.users.${user} = {
+    home = {
+      packages = with pkgs; [ protonup ];
+      sessionVariables.STEAM_EXTRA_COMPAT_TOOLS_PATHS = "${home}/.steam/root/compatibilitytools.d";
+    };
+  };
+}