refactor(jpush): update IOS notification alert format to use map

Change the `Alert` field in `IOSNotif` from a string to a map containing `title` and `body` to support structured notification content.

internal/pkg/jpush/client.go

@@ -386,11 +386,13 @@ func BuildNotification(title, body string, notificationType string, extras map[s
 			Priority: 1,
 		},
 		IOS: &IOSNotif{
-			Alert:          body,
-			Sound:          "default",
-			Badge:          "+1",
-			MutableContent: true,
-			Extras:         iosExtras,
+			Alert: map[string]any{
+				"title": title,
+				"body":  body,
+			},
+			Sound:  "default",
+			Badge:  "+1",
+			Extras: iosExtras,
 		},
 	}
 }