feat: review mobile update triage outcomes (Closes #765)

frontend/index.html

@@ -993,6 +993,10 @@
 <dialog class="mobile-queue-sheet" id="mobile-queue-sheet" aria-labelledby="mobile-queue-heading">
   <section class="mobile-queue-panel">
     <header><h2 id="mobile-queue-heading">Work queues</h2><button id="close-mobile-queues" type="button">Close</button></header>
+    <div id="mobile-update-outcome" class="mobile-update-outcome" role="status" aria-live="polite" hidden>
+      <p id="mobile-update-outcome-summary"></p>
+      <button id="review-kept-updates" type="button" hidden>Review kept unread</button>
+    </div>
     <p class="small muted">Choose what to work through next.</p>
     <div class="mobile-queue-list">
       <button data-mobile-queue="today" type="button"><span><strong>Today</strong><small>Planned work</small></span><span data-mobile-queue-count="today">0</span></button>