added error and not-implemented pages and placeholder ad graphic

ui/views/about.jet

@@ -1,3 +1,12 @@
+{*
+ * Amsterdam Web Communities System
+ * Copyright (c) 2025 Erbosoft Metaverse Design Solutions, All Rights Reserved
+ * 
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/.
+ *}
+<div class="flex">
     <!-- Venice Logo -->
     <div class="text-center mb-6">
         <img src="/img/builtin/AmsterdamLogo.png" 
@@ -48,4 +57,4 @@
                     class="w-72 h-25 mx-auto">
         </a>
     </div>
-</div>
+</div>