xdg-terminal-exec: define a .desktop file

hosts/common/programs/assorted.nix

@@ -902,7 +902,6 @@ in
     xwayland.sandbox.net = "clearnet";  #< just assuming this is needed (X11 traffic)
     xwayland.sandbox.whitelistDri = true;  #< would assume this gives better gfx perf
 
-    xdg-terminal-exec.sandbox.enable = false;  # xdg-terminal-exec is a launcher for $TERM
     xterm.sandbox.enable = false;  # need to be able to do everything
 
     yarn.persist.byStore.plaintext = [ ".cache/yarn" ];

hosts/common/programs/default.nix

@@ -112,6 +112,7 @@
     ./xdg-desktop-portal.nix
     ./xdg-desktop-portal-gtk.nix
     ./xdg-desktop-portal-wlr.nix
+    ./xdg-terminal-exec.nix
     ./xdg-utils.nix
     ./zeal.nix
     ./zecwallet-lite.nix

hosts/common/programs/xdg-terminal-exec.nix

@@ -0,0 +1,20 @@
+{ pkgs, ... }:
+{
+  sane.programs.xdg-terminal-exec = {
+    # give the package a .desktop item.
+    # this way anyone can launch a terminal via the xdg-desktop-portal.
+    packageUnwrapped = pkgs.xdg-terminal-exec.overrideAttrs (upstream: {
+      nativeBuildInputs = (upstream.nativeBuildInputs or []) ++ [
+        pkgs.copyDesktopItems
+      ];
+      desktopItems = (upstream.desktopItems or []) ++ [
+        (pkgs.makeDesktopItem {
+          name = "xdg-terminal-exec";
+          exec = "xdg-terminal-exec";
+          desktopName = "Default Terminal";
+        })
+      ];
+    });
+    sandbox.enable = false;  # xdg-terminal-exec is a launcher for $TERM
+  };
+}