Add push notifications

Push is optional. Customer messages and foreground live updates work without APNs. Add push when customers should receive replies while the app is inactive.

When the host app receives a device token, pass it to the messenger facade.

func application(
    _ application: UIApplication,
    didRegisterForRemoteNotificationsWithDeviceToken deviceToken: Data
) {
    Task { @MainActor in
        BTX.messenger.setDeviceToken(deviceToken)
    }
}

If the host app handles remote notifications manually, let BTX inspect the payload first. Non-BTX notifications remain under host-app control.

if BTX.isMessengerNotification(userInfo) {
    Task { @MainActor in
        _ = BTX.messenger.handleRemoteNotification(userInfo)
    }
    completionHandler(.noData)
    return
}

By default, BTX requests notification authorization the first time the messenger is presented. Disable automatic authorization when your app owns the permission prompt and its timing.

BTXConfiguration(
    publishableClientKey: "cfk_...",
    messengerOptions: BTXMessengerOptions(
        push: BTXPushConfiguration(
            automaticallyRequestsAuthorization: false
        )
    )
)

• Enable the messenger capability in BTX configuration.
• Configure APNs for the host application target.
• Forward the latest token after APNs registration succeeds.
• Give BTX only the notifications it recognizes.