Introduce Capability Registry & Discovery

tests/Fixtures/Enum/UnitEnum.php

@@ -0,0 +1,18 @@
+<?php
+
+/*
+ * This file is part of the official PHP MCP SDK.
+ *
+ * A collaboration between Symfony and the PHP Foundation.
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Mcp\Tests\Fixtures\Enum;
+
+enum UnitEnum
+{
+    case Yes;
+    case No;
+}