panel: show the send log's status as a badge

The send log was the one place in the panel where a status was bare text, next
to a delivery's own page where the same value is a badge, and a domain list
where the DNS verdict is one too — so a message's outcome looked like a
different kind of fact depending on which page you read it from.

The level travels on the row rather than being worked out in the template:
deliveryLevel is the one place that decides what a status means, the delivery
page already reads it, and a second mapping written into the template or the
stylesheet would have been free to drift from it. sent is ok, deferred a
warning, bounced and rejected errors, and queued unknown — nothing has gone
wrong, nothing has been reported yet.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

internal/web/view/templates/deliveries_rows.html

@@ -13,7 +13,7 @@
         <td>{{.From}}</td>
         <td>{{.To}}</td>
         <td class="subject"><span title="{{.Subject}}">{{.Subject}}</span></td>
-        <td class="status">{{.Status}}</td>
+        <td class="status"><span class="st st-{{.Level}}">{{.Status}}</span></td>
         <td class="actions"><a href="/deliveries/{{.ID}}?domain={{$.FilterDomain}}&app={{$.FilterApp}}&p={{$.Page}}">Details</a></td>
       </tr>
       {{end}}