add docker setup

docker-deploy/entrypoint-rspamd.sh

@@ -0,0 +1,19 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# Starts rspamd in the background, then hands off to mailgoserver as the container's
+# main (foreground) process.
+#
+# ponytail: no supervisor / restart-on-crash for rspamd here — if it dies mid-run, mail
+# keeps flowing without the extra scoring rather than the container crashing (the
+# built-in heuristic score in internal/mailstore/spam.go always runs regardless, and
+# CheckRspamd swallows connection errors rather than rejecting mail over them — see
+# internal/mailstore/rspamd.go). Add s6-overlay or supervisord if unattended rspamd
+# uptime matters more than that.
+rspamd -f &
+
+# Give rspamd's normal worker a moment to bind :11333 before the first message can
+# possibly arrive — purely cosmetic, mailgoserver degrades gracefully either way.
+sleep 1
+
+exec mailgoserver --host 0.0.0.0 "$@"