feat(games): add Hytale game module and Flatpak support

nixos/ryu/games/default.nix

@@ -0,0 +1,5 @@
+{...}: {
+  imports = [
+    ./hytale.nix
+  ];
+}

nixos/ryu/games/hytale.nix

@@ -0,0 +1,35 @@
+{pkgs, ...}: let
+  version = "2026.01.21-11273a4";
+  hytale-launcher = pkgs.fetchzip {
+    url = "https://launcher.hytale.com/builds/release/linux/amd64/hytale-launcher-${version}.zip";
+    sha256 = "sha256-PPdYmLxAVyqSkhulZXLcaEuhofCHZ4JcDJXIQ+lBhFg=";
+  };
+in {
+  environment.systemPackages = with pkgs; [
+    (pkgs.buildFHSEnv {
+      pname = "hytale";
+      inherit version;
+      targetPkgs = p:
+        with p; [
+          # Launcher
+          libsoup_3
+          gdk-pixbuf
+          glib
+          gtk3
+          webkitgtk_4_1
+
+          # Game
+          alsa-lib
+          icu
+          libGL
+          openssl
+          udev
+          xorg.libX11
+          xorg.libXcursor
+          xorg.libXrandr
+          xorg.libXi
+        ];
+      runScript = "${hytale-launcher}/hytale-launcher";
+    })
+  ];
+}