Ehmi/lb/notification backend

[echoEclectus]

This pull request introduces notification management features with real-time updates and UI enhancements, mainly by implementing new backend models for notifications, donations, and users, and updating project configuration and task tracking. The changes lay the groundwork for a more robust notification system, including user preferences and service architecture.

Backend model implementations:

• Added notification.model.js with a comprehensive schema for notifications, supporting multiple types, statuses, metadata, expiration, and user notification preferences for channels, types, and do-not-disturb settings.
• Added donation.model.js to handle donation records, including amount, currency, donor email, Stripe charge ID, status, and receipt URL.
• Refactored user.model.js to expand user schema with status, roles, block message, timestamps, and indexing for efficient queries.

Project configuration and tooling:

• Updated .dockerignore to exclude .env files for better security and cleaner Docker builds.