✅ Add metrics tracking for user creation and deletion

Implement metrics tracking for user_created and user_deleted during OmniAuth user creation and deletion processes. :lipstick: Update email templates for improved UI Revamp the email templates for event notifications and welcome emails to enhance user experience and readability. :lipstick: Update HTML structure and improve formatting Refactor various HTML files to enhance readability and maintainability. :sparkles: Add our single event pricing too :lipstick: Update event storage message for clarity Enhance the email notification to provide clearer information about photo storage duration based on event date.