vanishkaseakarvanishka-ux/AI-FAQ-Assistant-API ? reverse-engineered prompt

Build me a backend API for an AI FAQ and knowledge base app. I want users to sign up and log in with JWT, keep passwords hashed, and have normal user and admin roles. Users should be able to create, edit, delete, and view FAQs and categories, and search FAQs by keyword. Admins should manage categories and user roles.

Add an AI endpoint that answers questions using the saved FAQ content and stores the answer history. Please include MongoDB data models, validation, pagination, security headers, CORS, rate limiting, logging, and centralized error handling. Make it easy to run locally with env vars for the database, JWT secret, and Gemini API key.

If you need current docs for any dependency or API details, look them up online and wire it up cleanly.