Add comprehensive Chinese FAQ document for common SDK errors and solutions

[Copilot]

Created FAQ-CN.md documenting 24 common error cases based on source code analysis and existing GitHub issues.

Changes

• FAQ-CN.md: Comprehensive Chinese FAQ covering 9 categories of issues:

  • Environment variable configuration errors (empty AccessKey/Secret)
  • Config file parsing failures (invalid JSON, unsupported CloudSSO mode)
  • ECS RAM role issues (signal handling in threads, scheduler errors, metadata service failures)
  • OIDC authentication errors (missing required parameters, invalid session duration)
  • Async/threading problems (event loop in Python 3.10+, job serialization)
  • Logging configuration conflicts (global DEBUG level override)
  • Credential caching inconsistencies (mismatched AK/SK/token triplets)
  • Credentials URI problems (HTTPS support, response format)
  • Best practices (singleton pattern, secure credential management)

• README updates: Added FAQ references to guide users before opening issues

Content structure

Each FAQ entry includes:

• Error message and reproduction scenario
• Root cause analysis
• Multiple solution approaches with code examples
• References to related GitHub issues (error log #71, signal.signal should not be used in library code #67, caused by the local function refresh_task #66, Module-level loggers with explicit setLevel(DEBUG) ignore root logger configuration #65, Add CloudSSO mode support to cli_profile #64, Default credential provider behaviour #63, pypi上的1.0.0版本强制设置了全局的log等级为debug，建议调整 #58, Bug on the async related about get_event_loop with 1.0.0 #57, [Bug] Obtain inconsistent STS tokens #55, Credentials URI not support https #49, Missing parameter  #27)

Derived from analyzing 135+ exception raise points in codebase and 16 open/closed issues.

Original prompt

根据这个项目的源码， 帮我分析出出错的case，然后整理成中文的faq，也可以参考项目已经存在的issue，整体存在的issue和解决方案。每个faq的标题应该包含关键信息，答案应该简洁但表达直接。

---

✨ Let Copilot coding agent set things up for you — coding agent works faster and does higher quality work when set up for your repo.

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution.
_{You have signed the CLA already but the status is still pending? Let us recheck it.}