games/steam: Show icon in tray

Otherwise it just shows an ugly placeholder.

users/simon/modules/games.nix

@@ -72,6 +72,13 @@ let
         ''${SANDBOX_COMMAND:-${pkgs.unstable.steam}/bin/steam} \
         "$@"
   '';
+
+  steam-sandbox-with-icons = pkgs.runCommand "steam-sandbox-with-icons" { } ''
+    mkdir -p $out/{bin,share}
+    ln -s ${pkgs.steamPackages.steam}/share/icons $out/share
+    ln -s ${pkgs.steamPackages.steam}/share/pixmaps $out/share
+    ln -s ${steam-sandbox}/bin/steam-sandbox $out/bin/steam-sandbox
+  '';
 in
 lib.mkIf cfg.enable {
   home.packages = with pkgs; [ ]
@@ -87,6 +94,6 @@ lib.mkIf cfg.enable {
   }))
     ++ lib.optionals unfree.allowSoftware [
     unstable.osu-lazer-sandbox
-    steam-sandbox
+    steam-sandbox-with-icons
   ];
 }