refactor: isolate FastAPI and MySQL database implementation into fastapi_backend](url) folder

[vedant-kawale-27]

Summary

This PR reorganizes the repository by isolating the unused FastAPI implementation and its MySQL database dependencies into a dedicated top-level directory (fastapi_backend/).

While the production/docker-compose environments run the Flask-based ML API (api.py), this keeps the FastAPI code intact in a separate module so it can still be run and tested independently without cluttering the main backend directory.

Changes

• Module Reorganization: Moved the following FastAPI and MySQL files out of backend/ and into the new fastapi_backend/ folder:
  • main.py (FastAPI Server Entrypoint)
  • database.py (MySQL Database Client Helpers)
  • emails.py (FastAPI router for email operations)
  • export.py (FastAPI router for exporting reports)
  • middleware/logging_middleware.py (FastAPI logging middleware)
  • schema.sql (MySQL setup script)
• Local Dependency Setup: Created a standalone requirements.txt in the new fastapi_backend/ directory to document and isolate dependencies specific to this service (fastapi, uvicorn, mysql-connector-python, fpdf2, etc.).
• Relative Path & XAI Load Fix: Modified fastapi_backend/main.py to defer the initialization of XAIService until the models are loaded. This fixes path resolution issues and avoids double-loading pickles when running the application via uvicorn from the workspace root.
• Import Adjustments: Updated absolute imports inside fastapi_backend files to reference the new folder module prefix.
• Documentation: Updated the "Email Classification Database (FastAPI)" setup instructions in README.md to reference the new paths.

Verification

1. Verified that the module successfully loads:

   .\venv\Scripts\python.exe -c "import fastapi_backend.main"
   

closes #177

[vercel]

@vedant-kawale-27 is attempting to deploy a commit to the Aditya Sharma's projects Team on Vercel.

A member of the Team first needs to authorize it.

[Copilot]

Copilot was unable to review this pull request because the user who requested the review has reached their quota limit.