refactor: namespace-centric routes documentation

[DIYgod]

Summary

This PR redesigns the routes documentation from a category-based flat structure to a namespace-centric layout with list and detail pages.

Key Changes

• Namespace List Page: Displays all namespaces as cards with search, category filtering, sorting (heat/alphabetical), and feature filtering capabilities
• Namespace Detail Pages: Shows individual namespace information and all routes with a right-side navigation outline
• Components: Added NamespaceList, NamespaceDetail, and RouteOutline components for dynamic route rendering
• Data: Consolidated routes.json and categories.json for JSON-driven documentation
• Removed: Deleted 30 category-based markdown files and replaced with dynamic rendering
• Config: Simplified sidebar configuration

Test Plan

• Verify namespace list page displays all namespaces correctly
• Test search functionality across namespace and route names
• Verify category filter works properly
• Test sorting by heat and alphabetical order
• Test feature filters (Passed Test, No Anti-crawling, etc.)
• Verify detail pages load correctly with routes displayed
• Test right-side navigation outline on detail pages
• Verify multi-language support (en/zh) works for all new features

🤖 Generated with Claude Code

[safedep]

⚠️ Scan Failed: Pull Request Too Large

This pull request exceeds GitHub's diff limits and cannot be scanned.

GitHub Limits:

• Maximum 300 files per diff
• Maximum 1 MB total diff size

Recommendations:

• Split this PR into smaller, focused changes
• Review critical dependency changes manually
• Contact your team if this is blocking your workflow
  _{This report is generated by SafeDep Github App}

[netlify]

✅ Deploy Preview for rsshub-docs-next ready!

Name	Link
🔨 Latest commit	67d1709
🔍 Latest deploy log	https://app.netlify.com/projects/rsshub-docs-next/deploys/6959e315cf78e90008399ec3
😎 Deploy Preview	https://deploy-preview-144--rsshub-docs-next.netlify.app
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.

---

To edit notification comments on pull requests, go to your Netlify project configuration.