feat: 上线前安全加固与发布工程化；appmall 由插件迁移为独立应用

安全（P0）
- 发布包签名：新增 scripts/package_keygen.php、scripts/package_verify.php、
  ywxapp\service\PackageVerifier；FrameworkService::apply() 解压前强制验签
  （ywxapp.framework_package_verify，默认开启）
- JWT 收紧：config/jwt.php 移除公开默认密钥，JwtService::assertStrongSecret()
  校验非空 / 长度≥32 / 已知弱值；.env.production.example 键名由 JWT_SECRET_KEY 修正为 JWT_SECRET
- /api/v1/Article：免登录白名单收窄为只读接口，写操作字段白名单 + assertOwner() 越权校验
- 开发者令牌：查找接口不再回显明文、统一失败文案 + 限流
- TemplateInstaller：文件名白名单 + realpath 归一化 + 目录内断言，修复 Zip Slip；补 use ZipArchive
- 后台登录：接入验证码、失败锁定与登录限流（config/ratelimit.php）
- 缓存 / Session 驱动可由 .env 覆盖（CACHE_DRIVER / SESSION_TYPE），集群部署改 redis
- paycenter 支付日志开关改为 PAY_LOG，不再跟随 APP_DEBUG

工程化 / 交付
- 新增 CHANGELOG.md 与 .env.production.example；composer.lock 入库锁定依赖版本
- 插件离线安装 CLI 增加 --uid，后台上传安装透传 uid，付费插件授权校验可通过
- 授权拒绝文案区分「未携带 uid」与「未找到有效授权」，便于排障
- .gitignore 放行 .env.production.example / .env.addon.example / .gitattributes / public/.htaccess

结构
- appmall 由 addon/appmall 迁移为独立应用 app/appmall（市场 / 开发者中心 / 审核 / 分润）

addon/iot/menu.json

@@ -0,0 +1,29 @@
+{
+  "backend": [
+    {
+      "name": "iot",
+      "title": "MQTT代理",
+      "icon": "fa fa-sitemap",
+      "type": 1,
+      "sort": 60,
+      "status": 1,
+      "child": [
+        { "name": "iot/index", "title": "概览", "icon": "fa fa-dashboard", "type": 2, "sort": 1, "route": "/iot/backend/index" },
+        { "name": "iot/connections", "title": "客户端连接", "icon": "fa fa-plug", "type": 2, "sort": 2, "route": "/iot/backend/connections" },
+        { "name": "iot/messages", "title": "消息日志", "icon": "fa fa-envelope", "type": 2, "sort": 3, "route": "/iot/backend/messages" },
+        { "name": "iot/publish", "title": "发布消息", "icon": "fa fa-send", "type": 2, "sort": 4, "route": "/iot/backend/publish" },
+        { "name": "iot/auth", "title": "认证账号", "icon": "fa fa-user-secret", "type": 2, "sort": 5, "route": "/iot/backend/auth" },
+        { "name": "iot/acl", "title": "ACL规则", "icon": "fa fa-shield", "type": 2, "sort": 6, "route": "/iot/backend/acl" },
+        { "name": "iot/device", "title": "智能设备", "icon": "fa fa-cubes", "type": 2, "sort": 7, "route": "/iot/backend/device" },
+        { "name": "iot/scene", "title": "场景联动", "icon": "fa fa-magic", "type": 2, "sort": 8, "route": "/iot/backend/scene" },
+        { "name": "iot/group", "title": "设备分组", "icon": "fa fa-th-large", "type": 2, "sort": 9, "route": "/iot/backend/group" },
+        { "name": "iot/ota", "title": "OTA固件", "icon": "fa fa-cloud-upload", "type": 2, "sort": 10, "route": "/iot/backend/ota" },
+        { "name": "iot/alerts", "title": "告警中心", "icon": "fa fa-bell", "type": 2, "sort": 11, "route": "/iot/backend/alertsPage" },
+        { "name": "iot/rule", "title": "转发规则", "icon": "fa fa-exchange", "type": 2, "sort": 12, "route": "/iot/backend/rule" },
+        { "name": "iot/setting", "title": "服务设置", "icon": "fa fa-cog", "type": 2, "sort": 13, "route": "/iot/backend/setting" }
+      ]
+    }
+  ],
+  "member": [],
+  "frontend": []
+}