feat: build core architecture & implement user auth modules 🚀
feat: 搭建核心架构并实现用户认证模块 🚀
Framework Migration: Switched from Hertz to Gin, providing a more idiomatic and lightweight web foundation. ⚡
框架迁移：从 Hertz 切换至 Gin，构建了更符合 Go 惯例且轻量级的 Web 基础。⚡
Architectural Overhaul: Refactored the 3-layer architecture from global-variable-based calls to Explicit Dependency Injection (DI) via New... factory functions. This significantly improves testability and decoupling. 🏗️
架构重构：将三层架构从基于“全局变量”的调用重构为通过 New... 工厂函数实现的显式依赖注入 (DI)。这大幅提升了代码的可测试性与解耦程度。🏗️
User Auth: Completed and tested Register, Login, and Token Refresh APIs with robust error handling and Bcrypt password hashing. 🔐
用户认证：完成了注册、登录与 Token 刷新接口并通过测试，包含健壮的错误处理与 Bcrypt 密码哈希加密。🔐
Config Management: Integrated Viper for centralized, environment-aware configuration management. ⚙️
配置管理：集成了 Viper，实现了中心化且具备环境感知能力的配置管理。⚙️
DevOps & Docs:
Added docker-compose.yml for seamless MySQL 8.0 & environment setup. 🐳
Updated README.md with corrections for mistakes in image quoting and formats. 📝
运维与文档：
新增 docker-compose.yml，实现 MySQL 8.0 环境的一键启动。🐳
更新 README.md，修改了一些图片引用和格式上小错误。📝
