Async Notification Service

Build an async notification service using SQLAlchemy and FastAPI. The service manages user notifications.

Domain

• User: name, email (unique), created_at
• Notification: message (text), is_read (boolean, default false), created_at, belongs to a user

Requirements

Produce Python files in a src/ directory:

• src/database.py -- async engine configuration, async session factory, Base class, and async session dependency for FastAPI
• src/models.py -- User and Notification ORM models with their relationship
• src/main.py -- FastAPI app with these endpoints:
  • POST /notifications -- accepts JSON with user_id and message, creates a notification
  • GET /users/{user_id}/notifications -- returns all unread notifications for the user
  • PATCH /notifications/{notification_id}/read -- marks a notification as read

No test files, no migration files.