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/app/model/Permission.php

@@ -0,0 +1,55 @@
+<?php
+
+namespace app\model;
+
+use think\Model;
+
+class Permission extends Model
+{
+    protected $name = 'permissions';
+    protected $pk = 'id';
+    protected $autoWriteTimestamp = true;
+    protected $createTime = 'created_at';
+    protected $updateTime = 'updated_at';
+
+    // 权限枚举
+    const ALLOW_NO = 0;
+    const ALLOW_YES = 1;
+
+    // 数据模式枚举
+    const MODE_FILTER = 'filter';
+    const MODE_CUSTOM = 'custom';
+    const MODE_FULL = 'full';
+
+    /**
+     * 关联API密钥
+     */
+    public function apiKey()
+    {
+        return $this->belongsTo(ApiKey::class, 'api_key_id');
+    }
+
+    /**
+     * 检查是否允许访问接口
+     */
+    public function canAccess($endpoint)
+    {
+        if ($this->isFullData()) {
+            return true;
+        }
+        if ($endpoint === 'chuku') {
+            return $this->allow_chuku == self::ALLOW_YES;
+        } elseif ($endpoint === 'ruku') {
+            return $this->allow_ruku == self::ALLOW_YES;
+        }
+        return false;
+    }
+
+    /**
+     * 检查是否允许全量数据
+     */
+    public function isFullData()
+    {
+        return $this->allow_full_data == self::ALLOW_YES;
+    }
+}