[FEATURE] Add Swagger/OpenAPI documentation for Flask API endpoints

[Shikha18Shukla]

💡 Description

The backend currently does not have an OpenAPI configuration, making it difficult to extend the project with interactive API documentation in the future.

This issue adds the initial Flask-Smorest/OpenAPI setup by configuring the Flask application with the required API metadata and enabling the Swagger UI endpoint. This lays the foundation for documenting API routes incrementally without affecting existing functionality.

🎯 Motivation

• Prepare the backend for OpenAPI documentation
• Enable Swagger UI support for future API documentation
• Centralize API metadata configuration
• Make future endpoint documentation easier to implement

📋 Scope

• Add Flask-Smorest to the backend
• Configure OpenAPI metadata (API_TITLE, API_VERSION, OPENAPI_VERSION)
• Configure Swagger UI endpoint (/docs)
• Initialize the Flask-Smorest Api object
• Add comments describing future migration to documented Blueprints (if needed)

✅ Acceptance Criteria

• Flask-Smorest is integrated into the backend
• OpenAPI configuration is added to the Flask application
• Swagger UI is configured and accessible at /docs
• Existing API functionality remains unchanged
• Code is documented for future endpoint migration

📂 Expected Areas

backend/
├── app.py
└── requirements.txt

🏷️ Labels

ADVENTURER ELUSoC Feature Documentation

[mspandey]

pls assign it to me