Fix Postiz email sending — Resend API not being called

## Symptoms - Invite email HTML is generated and visible in Railway logs - Resend dashboard shows no API calls from Postiz - `RESEND_API_KEY`, `EMAIL_FROM_ADDRESS`, `EMAIL_FROM_NAME` all set correctly - Multiple redeploys didn't help - `DISABLE_REGISTRATION=true/false` doesn't affect the issue ## Env vars confirmed - `RESEND_API_KEY` = set (verified) - `EMAIL_FROM_ADDRESS` = `noreply@alert.optimified.com` - `EMAIL_FROM_NAME` = `Optimified` ## Next steps to investigate - Check Postiz source code for how `RESEND_API_KEY` is read — may need a different var name in Temporal version - Check if the Temporal worker handles email sending (not the main Postiz service) - Check GitHub issues for similar reports - Test with a fresh invite after clearing the database invite record