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.html

@@ -0,0 +1,8 @@
+{{define "content"}}
+<h1>Mail queue</h1>
+
+<div class="card">
+  <h2>Pending messages</h2>
+  {{template "mail_queue_body" .}}
+</div>
+{{end}}