feat(docs): enhance documentation and UI consistency

- Updated the index.html to dynamically set the theme color based on user selection, improving user experience during theme switching.
- Modified proxy.ts to include 'icon.png' in the matcher for better asset handling.
- Added a new icon.png file for enhanced branding.
- Improved metadata in layout.tsx and page.tsx files for better clarity and consistency in documentation.
- Updated various documentation files to reflect the new branding of 'Cursor Byok' and ensure consistent terminology throughout.
- Removed outdated blog entries and added new content to better align with the current product direction.

apps/docs/lib/i18n.ts

@@ -3,7 +3,8 @@ import { defineI18n } from 'fumadocs-core/i18n';
 export const i18n = defineI18n({
   defaultLanguage: 'zh',
   languages: ['zh', 'en'],
-  hideLocale: 'default-locale',
+  // 所有语言显式带前缀;未带前缀的访问由中间件按浏览器 Accept-Language 协商后重定向
+  hideLocale: 'never',
 });
 
 export type Language = (typeof i18n)['languages'][number];