fix(zeus): set XWayland primary monitor

configs/nixos/hosts/zeus/default.nix

@@ -1,6 +1,7 @@
 {
   config,
   lib,
+  pkgs,
   ...
 }:
 # zeus — Ryzen desktop with AMD graphics.
@@ -49,20 +50,29 @@
   modules.desktop.apps.steam.enable = true;
   modules.desktop.apps.discord.enable = true;
 
-  home-manager.users.${config.user.name}.wayland.windowManager.hyprland.settings.monitor = [
+  home-manager.users.${config.user.name}.wayland.windowManager.hyprland = {
-    {
+    settings.monitor = [
-      output = "HDMI-A-1";
+      {
-      mode = "1920x1080@120";
+        output = "HDMI-A-1";
-      position = "-1080x0";
+        mode = "1920x1080@120";
-      scale = 1;
+        position = "-1080x0";
-      transform = 3;
+        scale = 1;
-    }
+        transform = 3;
-    {
+      }
-      output = "DP-3";
+      {
-      mode = "2560x1440@239.96";
+        output = "DP-3";
-      position = "0x0";
+        mode = "2560x1440@239.96";
-      scale = 1;
+        position = "0x0";
-    }
+        scale = 1;
-  ];
+      }
+    ];
+
+    # Legacy games use XWayland's primary output to select their launch monitor.
+    extraConfig = ''
+      hl.on("hyprland.start", function()
+        hl.exec_cmd("${lib.getExe pkgs.xrandr} --output DP-3 --primary")
+      end)
+    '';
+  };
 
 }