ui(alerts): clarify Acknowledge vs Resolve (#9)

Co-authored-by: Steve Cliff <steve@devcloud.guru>
Co-committed-by: Steve Cliff <steve@devcloud.guru>

web/templates/pages/alerts.html

@@ -28,6 +28,13 @@
     </div>
   </div>
 
+  {{/* triage legend — Acknowledge vs Resolve looks identical on screen
+       (both leave the Open tab) so the difference needs spelling out. */}}
+  <div class="text-ink-mute mt-2 leading-[1.55]" style="font-size: 11.5px; max-width: 760px;">
+    <span class="text-ink-mid">Acknowledge</span> silences fan-out while the underlying problem is still happening — the alert moves to the Acknowledged tab.
+    <span class="text-ink-mid">Resolve</span> closes the alert; the next failure raises a fresh one with a new notification.
+  </div>
+
   {{/* filter strip */}}
   <div class="panel mt-4 px-4 py-3 rounded-[7px]"
        style="display: grid; grid-template-columns: auto auto auto 1fr; gap: 14px; align-items: center;">
@@ -89,7 +96,7 @@
     {{/* header row */}}
     <div class="alert-row head">
       <div></div>
-      <div>Severity / kind</div>
+      <div>Kind</div>
       <div>Host</div>
       <div>Message</div>
       <div>Raised</div>