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).

internal/web/templates/status.html

@@ -0,0 +1,43 @@
+{{define "content"}}
+<h1>Server status</h1>
+
+{{if .Flash}}<div class="flash">{{.Flash}}</div>{{end}}
+
+{{template "status_body" .}}
+
+<div class="card">
+  <h2>Hostname and reverse DNS <span class="st st-{{.PTR.Status}}">{{.PTR.Status}}</span></h2>
+  <p class="muted">Receiving servers check that the name this server announces
+  resolves to its address <em>and</em> that the address resolves back to the same
+  name (forward-confirmed reverse DNS). A missing or mismatched reverse record is
+  the most common reason self-hosted mail is rejected or scored as spam. The
+  reverse record is set at the hosting provider, not in the domain's DNS zone.</p>
+
+  <label>Server hostname</label>
+  <span class="code">{{if .Hostname}}{{.Hostname}}{{else}}(SELFPOST_HOSTNAME is not set){{end}}</span>
+
+  {{if .PTR.Records}}
+  <label>Forward and reverse lookup</label>
+  <span class="code">{{range .PTR.Records}}{{.}}
+{{end}}</span>
+  {{end}}
+
+  <p class="{{if eq .PTR.Status "ok"}}muted{{else}}error{{end}}">{{.PTR.Detail}}</p>
+
+  <form class="inline" method="post" action="/status/recheck">
+    <button type="submit">Re-check DNS</button>
+  </form>
+</div>
+
+<div class="card">
+  <h2>Configuration</h2>
+  <p class="muted">Regenerates the OpenDKIM and Postfix configuration from the
+  database and reloads both daemons. Use it if you edited the files by hand,
+  restored a backup, or the running configuration looks out of step with the
+  domain and application lists. It does not touch the mail queue or the TLS
+  certificate, and it is safe to run at any time.</p>
+  <form class="inline" method="post" action="/reload">
+    <button type="submit">Reload configuration</button>
+  </form>
+</div>
+{{end}}