Add comprehensive email setup review

Commit notes

- Reviewed email service architecture (Nodemailer/Resend abstraction) - Audited all 15 email templates for quality and completeness - Identified critical gap: email functions exist but are never called - Documented required integration points for each email type - Listed missing features (password reset, email verification) - Provided prioritized recommendations for implementation - Included testing instructions for local and production

Co-authored-by: armin.naimi <[email redacted]>