SmtpEmailService (nodemailer 9.0.5, exact-pinned) behind the existing EmailService seam. Provider resolution: EMAIL_PROVIDER wins, else RESEND_API_KEY selects Resend (hosted byte-identical), else SMTP_HOST selects SMTP. From header is built exactly like the Resend service after #1956 (no 'via <app>', fromAddress honored, platform-sender retry). STARTTLS is required by default (requireTLS) with SMTP_REQUIRE_TLS=false as an explicit opt-out for a plaintext LAN relay. Docs, env examples and the generated extension registry updated.
Jakob Wennberg
523fba0419