xF: tiniest AppKit steps

It's not quite possible to port the editor, so not finishing this.

xF.c

@@ -1325,6 +1325,7 @@ static void app_buffer_list_ensure_visible (const struct buffer *buffer);
 static void
 xui_request_attention (void)
 {
+	// NOTE: [NSApp requestUserAttention:NSInformationalRequest];
 #ifdef HAVE_X11
 	if (g_xui.ui != &x11_ui)
 		return;
@@ -4124,10 +4125,8 @@ app_process_mouse (termo_mouse_event_t type, int x, int y, int button,
 		if (!url)
 			return false;
 
-#ifdef HAVE_X11
-		if (g_xui.ui == &x11_ui)
+		if (g_xui.ui != &tui_ui)
 			app_open (url);
-#endif  // HAVE_X11
 		free (url);
 		return true;
 	}