feat(docs): add passkey internal docs

[NaveenChand755]

Summary

Added docs page for UserPasskeyMgmt component in the docs site.

Why

1. New component needs documentation so consumers know how to set it up and use it
2. Passkey setup has non-obvious requirements (custom domain, RP ID) that need to be clearly explained

What

1. New UserPasskeyMgmtDocs.tsx page with component preview, props table, TypeScript definitions, usage examples, and common issues
2. Added route /my-account/user-passkey-management in App.tsx
3. Added nav link in Layout.tsx
4. Added UserPasskeyMgmt card in the My Account overview page

Packages

• packages/core
• packages/react
• examples

References

Testing

How can this be verified? Note anything intentionally not covered by tests and why.

• This change adds unit test coverage
• Tested for both SPA and RWA flows, all example apps working
• All existing and new tests complete without errors

Checklist

• Breaking change
• Requires docs update
• Backward compatible

Contributing

• I have read the Auth0 general contribution guidelines
• I have read the Auth0 Code of Conduct

[github-actions]

🚀 Preview deployment

Branch: refs/pull/317/merge
Commit: 0fe3b3d

📝 Preview URL: https://auth0-universal-components-llr4zjq4e-ui-components-217de888.vercel.app

---

Updated at 2026-06-09T12:28:59.672Z

The base branch was changed.

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 89.75%. Comparing base (aecf241) to head (ec412ad).
⚠️ Report is 51 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #317      +/-   ##
==========================================
+ Coverage   89.47%   89.75%   +0.28%     
==========================================
  Files         156      162       +6     
  Lines       13070    13542     +472     
  Branches     1419     1797     +378     
==========================================
+ Hits        11694    12155     +461     
- Misses       1376     1387      +11     

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