release: 0.3.0: PTR fix via public resolvers; monitoring URLs and nav icons

panel: the PTR (reverse DNS) check no longer reports a correctly published
Fixed:
  - panel: the PTR (reverse DNS) check no longer reports a correctly published
Changed:
  - panel: the three monitoring pages now live at URLs that match their nav
  - panel: each entry in the navigation bar now carries an icon beside its label,
  - panel: the navigation bar is laid out as two rows on purpose — the signed-in

Full detail: CHANGELOG.md (0.3.0).

internal/web/templates/mail_queue_body.html

@@ -0,0 +1,6 @@
+{{define "mail_queue_body"}}
+<div id="mail-queue-body" hx-get="/mail-queue/body" hx-trigger="every 5s" hx-swap="outerHTML">
+  {{if .Error}}<p class="error">{{.Error}}</p>{{end}}
+  <span class="code">{{if .Output}}{{.Output}}{{else}}Queue is empty.{{end}}</span>
+</div>
+{{end}}