Live-update queue list when upload status changes

Storage.updatePhoto() now fires a 'photo-updated' CustomEvent so the
queue page refreshes immediately (300ms debounce) when the sync engine
changes a photo's status, instead of waiting for the 5s poll.

Also reduces background poll to 30s (just a fallback now), and revokes
stale ObjectURLs on each rebuild to prevent memory leaks.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

app/templates/queue.html

@@ -411,6 +411,10 @@ async function loadQueue() {
     }
 
     emptyState.style.display = 'none';
+    // Revoke old ObjectURLs before rebuilding to prevent memory leaks
+    queueList.querySelectorAll('img[src^="blob:"]').forEach(img => {
+        URL.revokeObjectURL(img.src);
+    });
     queueList.innerHTML = '';
 
     // Show active uploads first (newest first)
@@ -610,10 +614,23 @@ window.addEventListener('offline', () => {
     document.getElementById('sync-now-btn').disabled = true;
 });
 
-// Refresh queue periodically
+// Live updates: listen for photo status changes from the sync engine
+let refreshTimer = null;
+window.addEventListener('photo-updated', () => {
+    // Debounce: rapid status transitions (pending→uploading→verified)
+    // would otherwise trigger multiple full rebuilds
+    if (refreshTimer) clearTimeout(refreshTimer);
+    refreshTimer = setTimeout(() => {
+        refreshTimer = null;
+        loadQueue();
+        updateStats();
+    }, 300);
+});
+
+// Fallback: full refresh every 30s in case events are missed
 setInterval(() => {
     loadQueue();
     updateStats();
-}, 5000);
+}, 30000);
 </script>
 {% endblock %}