imaging: pause page auto-refresh while a LAPS QR is showing

meta http-equiv=refresh fires every 5s and reloads the entire page,
wiping the LAPS QR state mid-scan. Replaced the meta tag with a
JS-driven setTimeout(location.reload, 5000) so renderLapsQR() can
clearTimeout it. Reload resumes when the QR is cleared (manual or
60s auto). Multi-bay safety: only resumes if no other bay still has
a QR rendered.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

webapp/templates/imaging.html

@@ -2,7 +2,18 @@
 {% block title %}Imaging Progress - PXE Server Manager{% endblock %}
 
 {% block extra_head %}
-<meta http-equiv="refresh" content="5">
+{# JS-driven refresh instead of meta http-equiv so we can cancel it while a #}
+{# LAPS-password QR is showing (otherwise the 5s reload wipes the in-page  #}
+{# state every cycle).                                                     #}
+<script>
+function scheduleImagingReload() {
+  window._imagingReloadTimer = setTimeout(function() { location.reload(); }, 5000);
+}
+function cancelImagingReload() {
+  if (window._imagingReloadTimer) { clearTimeout(window._imagingReloadTimer); window._imagingReloadTimer = null; }
+}
+window.addEventListener('DOMContentLoaded', scheduleImagingReload);
+</script>
 {% endblock %}
 
 {% block content %}
@@ -240,6 +251,7 @@ function renderLapsQR(card) {
         container.innerHTML = qr.createImgTag(cellSize, 4);
         makeBtn.style.display  = 'none';
         clearBtn.style.display = '';
+        cancelImagingReload();  // freeze page refresh while QR is visible
         var remaining = 60;
         timerEl.textContent = '(auto-clears in ' + remaining + 's)';
         if (card._lapsTimer) clearInterval(card._lapsTimer);
@@ -264,6 +276,10 @@ function clearLapsQR(card) {
     timerEl.textContent = '';
     makeBtn.style.display  = '';
     clearBtn.style.display = 'none';
+    // Resume page refresh now that no QR is showing on any card.
+    if (!document.querySelector('.laps-qr-container img')) {
+        scheduleImagingReload();
+    }
 }
 document.addEventListener('click', function(e) {
     var card;