Adopt server examples

examples/01-discovery-stdio-calculator/server.php

@@ -0,0 +1,29 @@
+#!/usr/bin/env php
+<?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.
+ */
+
+require_once dirname(__DIR__).'/bootstrap.php';
+chdir(__DIR__);
+
+use Mcp\Server;
+use Mcp\Server\Transport\StdioTransport;
+
+logger()->info('Starting MCP Stdio Calculator Server...');
+
+Server::make()
+    ->withServerInfo('Stdio Calculator', '1.1.0', 'Basic Calculator over STDIO transport.')
+    ->withContainer(container())
+    ->withLogger(logger())
+    ->withDiscovery(__DIR__, ['.'])
+    ->build()
+    ->connect(new StdioTransport(logger: logger()));
+
+logger()->info('Server listener stopped gracefully.');