docs: 修复文档中过时的字段、签名和缺失的类

- BaseConfig 的 from_json/to_json → from_file/to_file
- InputConfig/ProcessingConfig/OutputConfig 字段对齐源码
- 移除不存在的 Registry 类，register() 去 category/priority
- SchedulerFactory.create 参数顺序修正
- 架构图/训练/参数文档补全 WSDScheduler
- CONTRIBUTING.md 克隆地址占位符修正
- params.md label_smoothing 默认值修正，补全 neftune_alpha
- app 类更正为 get_app 函数

CONTRIBUTING.md

@@ -5,7 +5,7 @@ Thank you for your interest in contributing! This document provides step-by-step
 ## Quick Start
 
 ```bash
-git clone https://github.com/your-username/AstrAI.git
+git clone https://github.com/ViperEkura/AstrAI.git
 cd AstrAI
 pip install -e ".[dev]"     # install with dev dependencies (pytest, ruff)
 ```