Capture the current architecture of the chatbot app in prose and diagrams (preferably mermaid) in an Architecture.md.

The document should encompass:

• overview
• backend
  • overview
  • directory/file structure
  • RAG
    • data ingestion pipeline
    • query pipeline
  • framework
  • endpoints
• frontend
  • overview
  • directory/file structure
  • framework
• deployment
  • infrastructure
  • secrets management