discord: patch to use wayland instead of X11/Xwayland

hosts/common/programs/discord.nix

@@ -1,13 +1,18 @@
-{ ... }: {
+{ lib, pkgs, ... }: {
   sane.programs.discord = {
+    # nixpkgs' discord defaults to X11 backend isntead of wayland, UNLESS NIXOS_OZONE_WL is specified.
+    # better to enable wayland support via package override instead of polluting the global env.
+    packageUnwrapped = pkgs.discord.overrideAttrs (base: {
+      installPhase = lib.replaceStrings [ "NIXOS_OZONE_WL" ] [ "WAYLAND_DISPLAY" ] base.installPhase;
+    });
+
     # creds, but also 200 MB of node modules, etc
     persist.byStore.private = [ ".config/discord" ];
-    suggestedPrograms = [ "xwayland" ];
     sandbox.wrapperType = "inplace";  #< package contains broken symlinks that my wrapper can't handle
     sandbox.whitelistAudio = true;
     sandbox.whitelistDbus = [ "user" ];  # needed for xdg-open
+    sandbox.whitelistDri = true;  #< required for even basic graphics (e.g. rendering a window)
     sandbox.whitelistWayland = true;
-    sandbox.whitelistX = true;
     sandbox.net = "clearnet";
     sandbox.extraHomePaths = [
       # still needs these paths despite it using the portal's file-chooser :?