fix: wait for service worker to activate before subscribing to push

navigator.serviceWorker.register() returns before the SW is active.
Use navigator.serviceWorker.ready which resolves only once a SW is
controlling the page, so pushManager.subscribe() always has an active SW.

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

1 files changed, 3 insertions, 6 deletions

diff --git a/web/app.js b/web/app.js
index 929b45d..eff8054 100644
--- a/web/app.js
+++ b/web/app.js
@@ -2634,12 +2634,9 @@ async function enableNotifications(btn) {
     if (!keyRes.ok) throw new Error(`Failed to get VAPID key: HTTP ${keyRes.status}`);
     const { public_key: vapidKey } = await keyRes.json();
 
-    // Register service worker.
-    const registration = await registerServiceWorker();
-    if (!registration) {
-      alert('Service worker registration failed.');
-      return;
-    }
+    // Register service worker and wait for it to become active.
+    await registerServiceWorker();
+    const registration = await navigator.serviceWorker.ready;
 
     // Subscribe via PushManager.
     const subscription = await registration.pushManager.subscribe({