fix(ios): unwrap optional title/body in dual-notification path

NotificationContent.title and .body are String?; assigning them to
non-optional String caused Swift build errors. Use ?? with the same
defaults as the config fallback so both branches yield non-optional
title/body.

ios/Plugin/DailyNotificationPlugin.swift

@@ -476,8 +476,8 @@ public class DailyNotificationPlugin: CAPPlugin {
         let title: String
         let body: String
         if useFetched {
-            title = fetchedContent.title
-            body = fetchedContent.body
+            title = fetchedContent.title ?? "Daily Notification"
+            body = fetchedContent.body ?? "Your daily update is ready"
         } else if fallbackBehavior == "show_default" {
             title = userNotification["title"] as? String ?? "Daily Notification"
             body = userNotification["body"] as? String ?? "Your daily update is ready"