Encapsulate session handling from protocol to new SessionManager (#247)

src/Server/Session/SessionManagerInterface.php

@@ -0,0 +1,47 @@
+<?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\Server\Session;
+
+use Symfony\Component\Uid\Uuid;
+
+/**
+ * Factory interface for creating session instances.
+ * This allows for different session implementations and custom initialization logic.
+ *
+ * @author Kyrian Obikwelu <koshnawaza@gmail.com>
+ */
+interface SessionManagerInterface
+{
+    /**
+     * Creates a new session with an auto-generated UUID.
+     * This is the standard factory method for creating sessions.
+     */
+    public function create(): SessionInterface;
+
+    /**
+     * Creates a session with a specific UUID.
+     * Use this when you need to reconstruct a session with a known ID.
+     */
+    public function createWithId(Uuid $id): SessionInterface;
+
+    /**
+     * Checks if a session with the given UUID exists.
+     */
+    public function exists(Uuid $id): bool;
+
+    /**
+     * Destroys the session with the given UUID.
+     */
+    public function destroy(Uuid $id): bool;
+
+    public function gc(): void;
+}