- Move Chinese docs to docs/zh-cn/ (44 md + RUNTIME_LIFECYCLE.html)
- Move existing English docs to docs/en/
- Translate all Chinese docs to English under docs/en/
- Update README.md links to docs/en/ and README-CN.md to docs/zh-cn/
- Create comprehensive guide for rebuilding PHPX WASM static library
- Document directory conventions and toolchain preparation steps
- Provide detailed instructions for daily development builds with CMake
- Include procedures for full SDK rebuild and PHP ABI changes
- Add validation steps and common error troubleshooting
- Update main documentation index with new rebuild guide link
