Dsm email service migration

[DerekMalone]

Changes

• Code reviewed by self
• Tests added/updated
• No console errors
• Branch up to date with main

Optional Notices

• Database migrations
• Docker rebuild required
• Will need to clear current users
• Email is currently defaulted to send to our forkbendz@gmail.com
  - Until a domain is established and an email account is verified with it, we can only register 1 user as we can only send to
  one email address until above occurs.

Env vars to add:

• RESEND_API_KEY - Get from Resend dashboard
• RESEND_FROM_EMAIL (optional) - Defaults to onboarding@resend.dev

Env vars to remove:

• SENDGRID_API_KEY
• SENDGRID_FROM_EMAIL

Description

Migrate email service from SendGrid to Resend for verification and password reset emails. Swaps the sendgrid package for resend, updates env var references, and refactors both send functions to use Resend's API.

Testing

• Registered new account in dev
• Verified email sent successfully via Resend dashboard

Commands Required for Testing or After Merge?

  # Rebuild backend for new dependency                                                                                                       
  docker compose build backend                                                                                                               
                                                                                                                                             
  # Restart containers                                                                                                                       
  docker compose down && docker compose up -d