release: 0.1.0: Phases 0-11: panel, Postfix/DKIM, milter, backup, Docker image

Initial feature-complete implementation of the v1.0 specification (phases 0-11 of `docs/implementation-plan.md`).
Added:
  - Panel (Go, single static binary) with SQLite persistence, one-time
  - Domain management with per-domain DKIM (RSA-2048, generated in pure Go) and
  - Application (sender identity) management: SASL credentials via `sasldb2`,
  - Full Postfix relay config generated from env at container start: SMTPS 465,
  - Journal milter (pure Go, `go-milter`) recording every send to `send_log`;
  … (6 more in CHANGELOG)

Full detail: CHANGELOG.md (0.1.0).

.gitignore

@@ -0,0 +1,13 @@
+# Development-only material (secrets, server access notes) — never published.
+dev/
+
+# Build artifacts (binaries are built on the dev server, not committed).
+/bin/
+*.exe
+
+# Local Go caches / test output, if ever present.
+*.out
+
+# e2e scratch stand (generated cert, DKIM zone, sink dump, /data bind mount)
+# — recreated fresh by every `make e2e` run, never checked in.
+/test/e2e/.stage/