Keep Mailpit as the backend's SMTP submission point and turn on its
relay so OTP/notification mail addressed to the owner reaches a real
Gmail inbox, while everything else stays captured-only.
- mailpit gains --smtp-relay-config + --smtp-relay-matching (default
non-routable, so an unconfigured stack only captures); relay.conf is
mounted from a new galaxy-dev-mailpit-config volume
- tools/dev-deploy/mailpit/relay.conf.tmpl + a dev-deploy.yaml step that
renders it from Gitea secrets (Gmail App Password, never committed)
and seeds the volume; the GALAXY_DEV_MAIL_RELAY_MATCH var drives the
relay-matching recipient
- backend SMTP config unchanged (still -> galaxy-mailpit:1025)
- dev-deploy README documents the relay + required secrets/vars
Verified locally: compose config valid; the rendered relay.conf is
accepted by mailpit v1.21.8 (relay + recipient-matching enabled).
Real Gmail delivery is verified at the dev-deploy preview once the
owner sets the secrets.
Ilia Denisov