add server-side code and mobile app code

server/vendor/symfony/service-contracts/Attribute/Required.php

@@ -0,0 +1,25 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Contracts\Service\Attribute;
+
+/**
+ * A required dependency.
+ *
+ * This attribute indicates that a property holds a required dependency. The annotated property or method should be
+ * considered during the instantiation process of the containing class.
+ *
+ * @author Alexander M. Turek <me@derrabus.de>
+ */
+#[\Attribute(\Attribute::TARGET_METHOD | \Attribute::TARGET_PROPERTY)]
+final class Required
+{
+}