Motivation:
Introduce a dedicated translation node for simplified workflows, enhance error logging, and make the project accessible to a global audience with a default English README.
Implementation:
1. Implemented LLMTranslator node with auto-language detection and glossary support.
2. Enhanced OpenAICompatibleLoader with request size tracking and detailed error diagnostics.
3. Renamed README.md -> README_CN.md and created a new idiomatic English README.md with language switchers.
4. Added docs/llm_translator_guide.md and removed redundant docs/readme_en.md.