refactor(deps): remove deprecated @github/webauthn-json

[xrgzs]

Description / 描述

• Update WebAuthn integration to use native PublicKeyCredential methods

Motivation and Context / 背景

#51 and pnpm:

Warning

The following dependencies are either deprecated or have replacements available.

Datasource	Package	Replacement PR?
npm	@github/webauthn-json

How Has This Been Tested? / 测试

添加webauthn正常
使用webauthn登录正常

Checklist / 检查清单

• I have read the CONTRIBUTING document.
  我已阅读 CONTRIBUTING 文档。
• I have formatted my code with go fmt or prettier.
  我已使用 go fmt 或 prettier 格式化提交的代码。
• I have added appropriate labels to this PR (or mentioned needed labels in the description if lacking permissions).
  我已为此 PR 添加了适当的标签（如无权限或需要的标签不存在，请在描述中说明，管理员将后续处理）。
• I have requested review from relevant code authors using the "Request review" feature when applicable.
  我已在适当情况下使用"Request review"功能请求相关代码作者进行审查。
• I have updated the repository accordingly (If it’s needed).
  我已相应更新了相关仓库（若适用）。
  • OpenList-Frontend #XXXX
  • OpenList-Docs #XXXX