refactor: transport agnostic examples (#131)

examples/stdio-custom-dependencies/Service/StatsServiceInterface.php

@@ -1,20 +0,0 @@
-<?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\Example\StdioCustomDependencies\Service;
-
-interface StatsServiceInterface
-{
-    /**
-     * @return array<string, int>
-     */
-    public function getSystemStats(): array;
-}