feat(training): 添加训练模块基础架构
实现 Commit 1：训练模块基础架构
新增文件：
- src/training/__init__.py - 主模块导出
- src/training/components/__init__.py - components 子模块导出
- src/training/components/base.py - BaseModel/BaseProcessor 抽象基类
- src/training/registry.py - 模型和处理器注册中心
- tests/training/test_base.py - 基础架构单元测试
功能特性：
- BaseModel: 提供 fit, predict, feature_importance, save/load 接口
- BaseProcessor: 提供 fit, transform, fit_transform 接口
- ModelRegistry/ProcessorRegistry: 支持装饰器风格组件注册
- 支持即插即用的组件扩展机制
Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-opencode)
Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>
liaozhaorun
472b2b665a