- Renamed DATABASE_URL to POSTGRES_URL in .env.example for clarity.
- Added SMTP configuration for email sending, including host, port, user, password, and from address.
- Updated package.json to include new dependencies for email handling and UI components.
- Modified middleware to handle public and protected routes more effectively.
- Enhanced API routes for studies to support user roles and permissions.
- Updated database schema to include invitations and user roles related to studies.
- Improved user permissions handling in the permissions module.
- Added new utility functions for managing user roles and study access.
