Refactor the frontend to use a more consistent design system and improve the overall user interface and experience.
- Implement a consistent use of `Card` components across various pages (Dashboard, Settings, Notes, etc.).
- Improve layout responsiveness and spacing in several modules.
- Enhance the Tasks page with drag-and-drop status updates and a Kanban-style view.
- Update the Calendar view with better color coding for task priorities and types.
- Refactor the Bookmarks page to use a grid layout with improved card previews.
- Update the Nginx configuration to handle SPA routing and health checks more effectively.
- Standardize import paths using `@/` aliases.
- Fix minor bugs in message sending and loading states.
- Update Docker configuration to build from source and use a specific backend port.
