[Feature] 添加基于 Python texture 库的设置标签页 / Add Settings Tab Based on Python texture Library

[SunYanbox]

• 新增一个设置标签页，UI 使用 Python texture 库实现，用于集中管理应用配置（如环境变量、主题、路径等）。
  Add a new settings tab with UI built using the Python texture library, used for centralized management of application configurations (e.g., environment variables, theme, paths, etc.).

• 该标签页应支持环境变量的查看、新增、编辑和删除，并且修改后可以即时生效或提示重启。
  This tab shall support viewing, adding, editing, and deleting environment variables, with changes either taking effect immediately or prompting for a restart.

• 设置数据需持久化保存（如本地配置文件或注册表），下次启动时自动加载。
  Settings data must be persisted (e.g., local config file or registry) and automatically loaded on next startup.