Refactor Milvus collection management: streamline error handling during collection drops in cleanup and startup processes, ensuring defensive programming practices. Remove redundant drop logic from cleanup function.

Add reset index functionality: implement reset_index function to drop the collection in Milvus and add UI elements for resetting the index in the app interface.

Implement collection management in Milvus: drop collection during cleanup and on startup if no documents exist. Update embedding generation to clarify data types and improve error handling. Refactor vector store collection creation logic to avoid unnecessary drops.

Refactor imports and improve code formatting across multiple files for better readability and organization.

Add initial implementation of the RAG application with Gradio interface