Move examples to server directory (#198)

* move examples to server directory

This will prepare for the client implementation in https://github.com/modelcontextprotocol/php-sdk/pull/192

* fix move bootstrap too

examples/server/bootstrap.php

@@ -0,0 +1,88 @@
+<?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.
+ */
+
+use Http\Discovery\Psr17Factory;
+use Laminas\HttpHandlerRunner\Emitter\SapiEmitter;
+use Mcp\Capability\Registry\Container;
+use Mcp\Server\Transport\StdioTransport;
+use Mcp\Server\Transport\StreamableHttpTransport;
+use Mcp\Server\Transport\TransportInterface;
+use Psr\Http\Message\ResponseInterface;
+use Psr\Log\AbstractLogger;
+use Psr\Log\LoggerInterface;
+
+require_once dirname(__DIR__, 2).'/vendor/autoload.php';
+
+set_exception_handler(function (Throwable $t): never {
+    logger()->critical('Uncaught exception: '.$t->getMessage(), ['exception' => $t]);
+
+    exit(1);
+});
+
+/**
+ * @return TransportInterface<int>|TransportInterface<ResponseInterface>
+ */
+function transport(): TransportInterface
+{
+    if ('cli' === \PHP_SAPI) {
+        return new StdioTransport(logger: logger());
+    }
+
+    return new StreamableHttpTransport(
+        (new Psr17Factory())->createServerRequestFromGlobals(),
+        logger: logger(),
+    );
+}
+
+function shutdown(ResponseInterface|int $result): never
+{
+    if ('cli' === \PHP_SAPI) {
+        exit($result);
+    }
+
+    (new SapiEmitter())->emit($result);
+    exit(0);
+}
+
+function logger(): LoggerInterface
+{
+    return new class extends AbstractLogger {
+        public function log($level, Stringable|string $message, array $context = []): void
+        {
+            $debug = $_SERVER['DEBUG'] ?? false;
+
+            if (!$debug && 'debug' === $level) {
+                return;
+            }
+
+            $logMessage = sprintf(
+                "[%s] %s %s\n",
+                strtoupper($level),
+                $message,
+                ([] === $context || !$debug) ? '' : json_encode($context),
+            );
+
+            if (($_SERVER['FILE_LOG'] ?? false) || !defined('STDERR')) {
+                file_put_contents('dev.log', $logMessage, \FILE_APPEND);
+            } else {
+                fwrite(\STDERR, $logMessage);
+            }
+        }
+    };
+}
+
+function container(): Container
+{
+    $container = new Container();
+    $container->set(LoggerInterface::class, logger());
+
+    return $container;
+}