This commit implements the addition of `target_owners` and `alert_notification_events` tables, enabling management of responsible users for targets. Backend and frontend components are updated to allow viewing, assigning, and notifying target owners about critical alerts via email.
This commit introduces alert management capabilities, including creating, updating, listing, and removing custom SQL-based alerts in the backend. It adds the necessary database migrations, API endpoints, and frontend pages to manage alerts, enabling users to define thresholds and monitor system health effectively.
