Feature Request: Implementation of a Comprehensive Email Notification System

[Chautoo]

While Pelican already supports various Mail Drivers (SMTP, Mailgun, Mandrill, Postmark, etc.), the current implementation for actual triggered user notifications is limited. To improve User Experience and security, I propose a more robust email notification system that handles automated life-cycle emails and administrative alerts.

I would like to see the following events integrated into the panel's core to trigger automated emails:

• Welcome Email: Automatically sent when a new user account is created (manually by admin or via API), including a link to set their initial password.
• Password Reset/Forgot Password: Standardized flow for users to regain access.
• Email Change Verification: When a user or admin changes the account email, a verification link should be sent to the new address.
• 2FA Status Changes: Notification when Two-Factor Authentication is enabled or disabled.
• Server Transfer/Creation: Notify users when a server has been successfully transferred to their account.
• Node/Service Alerts: Optional alerts for admins if a node goes offline or resources are critically low.
• Manual User Mailing: A feature for admins to send a manual broadcast email to all users (e.g., for maintenance announcements).