- Add --chunk-size and --chunk-overlap parameters to all RAG examples
- Preserve original default values for each data source:
- Document: 256/128 (optimized for general documents)
- Email: 256/25 (smaller overlap for email threads)
- Browser: 256/128 (standard for web content)
- WeChat: 192/64 (smaller chunks for chat messages)
- Make --file-types optional filter instead of restriction in document_rag
- Update README to clarify interactive mode and parameter usage
- Fix LLM default model documentation (gpt-4o, not gpt-4o-mini)