Add language detection to homepage redirect for zh→cn mapping

[Copilot]

Plan: Homepage Auto-Redirect to Current Language

Issue Understanding

The homepage (root /) should automatically redirect to the appropriate language version based on:

• User's browser language preferences (Accept-Language header)
• Fallback to default language if user's preferred language is not available

Root Cause

Without a root page.tsx file, Next.js doesn't recognize / as a valid route, so the middleware/proxy never gets invoked for homepage requests.

Solution Implemented

1. Modified proxy.ts to add custom language detection for root path (commit 4b70311)
2. Added app/page.tsx to ensure Next.js recognizes the root route (this commit)

The proxy intercepts / requests and redirects based on Accept-Language header:

• zh-* → /cn/docs
• All other → /en/docs

Testing Results

✅ Chinese users (Accept-Language: zh-CN) → /cn/docs
✅ English users (Accept-Language: en-US) → /en/docs
✅ Users without language preference → /en/docs (default)

Changes Checklist

• Modified proxy.ts to handle root path with custom language detection
• Added app/page.tsx to enable middleware for homepage route
• Verified build includes root route
• Tested language detection with different Accept-Language headers
• Confirmed redirects work correctly

Original prompt

首页应该可以自动跳转到可用的语言中的当前语言

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Project	Deployment	Review	Updated (UTC)
docs	Ready	Preview, Comment	Jan 18, 2026 1:29am

[github-actions]

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Preview Links

• 📝 Documentation: Will be available once Vercel deployment completes
• 🌍 Languages: English (/en/docs) and Chinese (/cn/docs)

Build Status

Check the CI workflow for build status and any errors.

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Automated preview information for PR #47

[huangyiirene]

@copilot 为什么我没有跳转成功？

[Copilot]

@copilot 为什么我没有跳转成功？

问题已修复！之前缺少根页面文件导致Next.js无法识别 / 路由，所以中间件没有被调用。

已添加 app/page.tsx 文件 (commit b9548d0)，现在跳转功能正常工作：

• 中文浏览器 (zh-CN) → 自动跳转到 /cn/docs ✅
• 英文浏览器 (en-US) → 自动跳转到 /en/docs ✅