feat(tests): add comprehensive tests for TokenRouter and related components

- Implement tests for TokenRouter downstream policy, covering allowedRouteIds and site weight multipliers.
- Add tests for TokenRouter patterns and model mapping, including regex pattern matching and model mapping precedence.
- Create tests for BrandIcon component to verify brand detection logic.
- Develop tests for Accounts page, focusing on rebind panel behavior and refresh action on error.
- Introduce fuzzy search utility tests to validate substring and subsequence matching.
- Implement navigation focus helpers tests for building and parsing focus paths.
- Add progressive render tests to ensure correct initial and next visible counts.
- Create route model candidates index tests to validate route candidate indexing and matching logic.

docs/index.md

@@ -0,0 +1,51 @@
+---
+layout: home
+
+hero:
+  name: "Metapi 文档中心"
+  text: "中转站的中转站"
+  tagline: "将分散的 AI 中转站聚合为一个统一网关"
+  image:
+    src: /logos/logo-full.png
+    alt: Metapi
+  actions:
+    - theme: brand
+      text: 10 分钟快速上手
+      link: /getting-started
+    - theme: alt
+      text: 常见问题 FAQ
+      link: /faq
+    - theme: alt
+      text: 贡献教程/FAQ
+      link: /community/faq-tutorial-guidelines
+
+features:
+  - title: 快速上手
+    details: 从部署到第一条请求，按步骤完成最小可用环境搭建。
+    link: /getting-started
+  - title: 问题排查
+    details: 汇总高频报错、根因定位和标准修复路径，降低重复沟通成本。
+    link: /faq
+  - title: 运维与配置
+    details: 覆盖部署、配置、监控、备份、升级回滚等生产场景。
+    link: /operations
+---
+
+## 文档定位
+
+- 面向新用户：快速搭建和接入
+- 面向维护者：稳定运行、排障和升级
+- 面向贡献者：持续沉淀教程、FAQ 与最佳实践
+
+## 推荐阅读路径
+
+1. [快速上手](/getting-started)
+2. [部署指南](/deployment)
+3. [配置说明](/configuration)
+4. [客户端接入](/client-integration)
+5. [常见问题 FAQ](/faq)
+
+## 协作维护
+
+如需新增文档内容，请优先使用统一模板与提交流程：  
+[FAQ/教程贡献规范](/community/faq-tutorial-guidelines)