feat(quiver): reposition URL comment in latex export

modules/nixos/deertopia/quiver.nix

@@ -4,12 +4,17 @@ let cfg = config.sydnix.deertopia.quiver;
 in {
   options.sydnix.deertopia.quiver = {
     enable = lib.mkEnableOption "Quiver, a commutative diagram editor";
+    package = lib.mkPackageOption sydpkgs.packages.${system} "quiver" {};
   };
 
   config = lib.mkIf cfg.enable {
     sydnix.deertopia.nginx.vhosts."q".vhost =
       let
-        package = sydpkgs.packages.${system}.quiver;
+	package = cfg.package.overrideAttrs (finalAttrs: prevAttrs: {
+	  patches = (prevAttrs.patches or []) ++ [
+	    ./quiver/move-export-url.patch
+	  ];
+	});
       in {
         forceSSL = true;
         enableACME = true;