Fix HuggingFace Spaces import error with lazy loading

Refactor Gradio UI components and add configuration class for improved maintainability

Update dependencies and refactor agent initialization; add optional fact-check skipping for performance improvements

Refactor RAG Email Assistant for in-memory processing; update configurations, implement memory indexing and retrieval, enhance Gradio UI, and streamline document ingestion.

Implement modular RAG email assistant architecture