Adds outbound mail for linked-email verification: EMAIL_PROVIDER=smtp + SMTP_*
app env (submits via the cluster mailserver as spam@, relayed by Brevo),
SMTP_PASSWORD mapped to the existing PLANS_IMAP_PASSWORD (no new secret), and a
token-gated /api/emails/confirm ingress carve-out (auth=none, like the calendar
feed). Applied locally via scripts/tg.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>