RAG on PostgreSQL

1. Copy .env.sample into a .env file.

2. Run these commands to install the web app as a local package (named rag_app), set up the local database, and seed it with test data:

   python -m pip install -e src/backend
   python ./src/backend/rag_app/setup_postgres_database.py
   python ./src/backend/rag_app/setup_postgres_seeddata.py

3. Run the FastAPI backend (with hot reloading). This should be run from the root of the project:

   python -m uvicorn rag_app:create_app --factory --reload