Improve UnifiedPush reset UX: poll for endpoint and clearer status.

src/app/utils/backgroundSync.ts

@@ -542,7 +542,18 @@ export const requestResetPushRegistration = async (): Promise<{ success: boolean
     const MatrixBackgroundSync = registerPlugin<MatrixBackgroundSyncPlugin>('MatrixBackgroundSync');
     const result = await MatrixBackgroundSync.requestDistributorSetup();
     console.log('[BackgroundSync] requestDistributorSetup completed:', result);
-    return result ?? { success: false };
+    if (!result?.success) return { success: false };
+
+    // Endpoint arrives asynchronously from the distributor after register().
+    for (let i = 0; i < 20; i += 1) {
+      await new Promise((resolve) => setTimeout(resolve, 250));
+      const status = await getBackgroundSyncStatus();
+      if (status?.registered && status.endpoint) {
+        return { success: true };
+      }
+    }
+
+    return { success: true };
   } catch (err) {
     console.error('[BackgroundSync] requestDistributorSetup failed:', err);
     return { success: false };