docs: 重构 README 结构，全文档添加目录导航

- README 新增 Getting Started 端到端流程，整合快速开始与演示，去重精简
- 中文 README 同步英文版结构，预处理配置改用 seq 策略
- inference.md 补充 SSE 流式格式、错误响应、/stats 端点文档
- params.md 扩展为 CLI 参考，覆盖 server/generate/preprocess 参数表
- dataflow.md 拆分 tokenization/format detection/backend 子节，新增流程图
- architecture/training/inference/preprocessing 均添加目录导航
- 移除 README CI badge

assets/docs/architecture.md

@@ -1,5 +1,12 @@
 # AstrAI Architecture
 
+## Contents
+
+- [Class Diagram](#class-diagram) — Full Mermaid class diagram across 10+ namespaces
+- [Module Overview](#module-overview) — Component inventory per module
+- [Design Patterns](#design-patterns) — 13 documented patterns with classes
+- [Core Relationships](#core-relationships) — 11 key inter-component relationships
+
 ## Class Diagram
 
 ```mermaid