enable gamescope, add hyprland cs2 window rule

configs/hypr/rules.lua

@@ -65,3 +65,7 @@ for _, fo_inhib in ipairs(focus_inhibits) do
     idle_inhibit = "focus",
   })
 end
+
+hl.window_rule({
+  match = { class = "cs2" }, immediate = true
+})

hosts/graphical/configuration.nix

@@ -138,9 +138,14 @@
         };
       };
     };
+    gamescope = {
+      enable = true;
+      capSysNice = true;
+    };
 
     steam = {
       enable = true;
+      gamescopeSession.enable = true;
       remotePlay.openFirewall = true;
       dedicatedServer.openFirewall = true;
     };