panel-notifications: Account, Server > Settings, Server > Health, help; e2e

The pages of the mockups accepted in 87fa0a4, built from the kit's partials
(written by a Sonnet agent into the working tree, reviewed here):

- Account: "Send me notifications" in the Profile form, saved with the
  profile; an unticked box is off.
- Server > Settings: the instance switch (box 03), and box 04 Notification
  mail with the DKIM and SPF records of the server's own name, drawn with the
  record partial of a domain's DNS page and checked in DNS. Sending rate
  limits are box 02 in the left column. A record that is not in place is
  tagged as a warning, not a failure: notifications are sent without it.
- Server > Health: card 06 Notification mail with the state of each record
  and a link to Settings, beside Configuration (07); part of the polled
  fragment; Re-check DNS forces it too. Overview does not run this check.
- help.go: the Notifications topic and the clauses in Settings and Your
  account, word for word with help.html.

If the server's key cannot be read the pages still render: the DKIM record
is left out and SPF is shown unchecked.

e2e: the administrator gets a mailbox behind the sink and the server's DKIM
record from Settings is published; the level-2 refusal of the next step must
then arrive as a notification from postmaster@mail.e2e.test, signed as that
name with the key Settings shows, and must not be a row of the Outbound log.
The rotation step now waits for Postfix to be running: it follows a step that
restarts the container, and logrotate's `postfix reload` failed in between.

On the test server, for this tree: go vet clean, go test ./... 23 packages
ok, make e2e ok (147 s); the notification reached the sink 28 s after the
refusal.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

internal/web/view/templates/health.html

@@ -1,17 +1,23 @@
 {{/* Server > Health (mockup health.html): every check behind the cards of
      Overview, and the one action that is not about DNS, Reload configuration. The
-     two rows of tables are the polled part (health_body.html); the head and the
-     Configuration box are static. */}}
+     two rows of tables are the polled part (health_body.html), and so is the
+     Notification mail card (health_mail), which sits in the last row beside the
+     static Configuration box. */}}
 {{define "content"}}
 {{template "page_head" .Head}}
 {{if .Flash}}{{template "flash" .Flash}}{{end}}
 
 {{template "health_body" .}}
 
-{{template "box_open" .Configuration}}
-{{template "body_open"}}
-<p class="mb-3">Regenerates the OpenDKIM and Postfix configuration from the database and reloads both daemons. Use it after editing the files by hand, after restoring a backup, or when the running configuration looks out of step with the domain and application lists. It does not touch the queue or the TLS certificate.</p>
-{{template "action" .Reload}}
-{{template "body_close"}}
-{{template "box_close"}}
+<div class="columns">
+  {{template "health_mail" .}}
+  <div class="column is-6">
+    {{template "box_open" .Configuration}}
+    {{template "body_open"}}
+    <p class="mb-3">Regenerates the OpenDKIM and Postfix configuration from the database and reloads both daemons. Use it after editing the files by hand, after restoring a backup, or when the running configuration looks out of step with the domain and application lists. It does not touch the queue or the TLS certificate.</p>
+    {{template "action" .Reload}}
+    {{template "body_close"}}
+    {{template "box_close"}}
+  </div>
+</div>
 {{end}}