feat: update ready keeps showing even after updating

Task #61 completed by ClaudeQueue

ClaudeQueue

frontend/app.js

@@ -2992,17 +2992,34 @@ function showUpdateBanner() {
     { label: 'Later', onClick: closeModal },
     { label: 'Refresh UI', primary: true, onClick: async () => {
       closeModal();
-      await hardReloadUI();
+      await applyUpdate();
     }},
   ]);
 }
 
+// Tracks the current SW registration so applyUpdate() can reach the
+// waiting worker without re-querying getRegistration().
+let _swReg = null;
+
+// Applies a pending SW update in place (see sw-update.js for the full
+// rationale — this used to call hardReloadUI(), which caused the "Update
+// ready" banner to reappear right after being applied).
+async function applyUpdate() {
+  const reg = _swReg || (('serviceWorker' in navigator) ? await navigator.serviceWorker.getRegistration() : null);
+  await window.SwUpdate.applyUpdate({
+    reg,
+    container: navigator.serviceWorker,
+    reload: () => window.location.reload(),
+  });
+}
+
 async function registerServiceWorker() {
   if (!WEB || !('serviceWorker' in navigator)) return;
   try {
     // updateViaCache:'none' prevents the browser from serving a stale
     // cached copy of sw.js — the server always returns it fresh (no-store).
     const reg = await navigator.serviceWorker.register('/sw.js', { updateViaCache: 'none' });
+    _swReg = reg;
 
     // If a new SW is already waiting (e.g. user refreshed after an update),
     // show the dialog right away.