Split testsuite for unit and inspector based tests (#82)

tests/Unit/Capability/Discovery/Fixtures/SubDir/HiddenTool.php

@@ -0,0 +1,22 @@
+<?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\Unit\Capability\Discovery\Fixtures\SubDir;
+
+use Mcp\Capability\Attribute\McpTool;
+
+class HiddenTool
+{
+    #[McpTool(name: 'hidden_subdir_tool')]
+    public function run()
+    {
+    }
+}