feat(composer): 添加数据库迁移工具phinx依赖

- 在composer.json中添加robmorgan/phinx依赖项
- 设置phinx版本约束为^0.16.10
- 确保PHP版本要求兼容phinx运行环境

composer.json

@@ -8,6 +8,7 @@
   ],
   "require": {
     "php": ">=8.3",
+    "robmorgan/phinx": "^0.16.10",
     "six-shop/core": ">=0.6 <1.0"
   },
   "authors": [