feat: 初始化进销存数据开放平台项目

初始化完整的前后端项目结构，包含ThinkPHP后端API服务和Next.js前端管理系统，添加基础配置、中间件、模型、路由等核心代码，以及项目文档和静态资源。

thinkphp/public/router.php

@@ -0,0 +1,19 @@
+<?php
+// +----------------------------------------------------------------------
+// | ThinkPHP [ WE CAN DO IT JUST THINK ]
+// +----------------------------------------------------------------------
+// | Copyright (c) 2006~2019 http://thinkphp.cn All rights reserved.
+// +----------------------------------------------------------------------
+// | Licensed ( http://www.apache.org/licenses/LICENSE-2.0 )
+// +----------------------------------------------------------------------
+// | Author: liu21st <liu21st@gmail.com>
+// +----------------------------------------------------------------------
+// $Id$
+
+if (is_file($_SERVER["DOCUMENT_ROOT"] . $_SERVER["SCRIPT_NAME"])) {
+    return false;
+} else {
+    $_SERVER["SCRIPT_FILENAME"] = __DIR__ . '/index.php';
+
+    require __DIR__ . "/index.php";
+}