Auto-update specific channels in the background without enabling notifications

[ProtoUI]

Checklist

• I made sure that there are no existing issues - open or closed - which I could contribute my information to.
• I have read the FAQ and my problem isn't listed.
• I'm aware that this is a request for NewPipe itself and that requests for adding a new service need to be made at NewPipeExtractor.
• I have taken the time to fill in all the required details. I understand that the feature request will be dismissed otherwise.
• This issue contains only one feature request.
• I have read and understood the contribution guidelines.
• I have read and understood the AI policy. The content of this request is not generated by AI.

Feature description

I would like a feature that allows users to select specific channels to automatically check for new videos in the background, without triggering system notifications. The goal is to have the feed already up-to-date when opening the app. From an implementation standpoint, you could reuse the existing "Channel selection for notifications" logic, but decouple it from the Android notification system so it simply updates the feed silently.

Why do you want this feature?

Currently, the only way to have the app automatically fetch new videos from specific channels before opening it is to enable notifications for those channels. I don't want push notifications; I just want the convenience of a ready-to-view feed upon launch without having to manually pull to refresh and wait. Furthermore, this limitation is worsened by the recurring notifications bug (#8684). Because I am forced to use the notification system just to keep my feed updated, my device gets spammed with notifications.

Additional information

Separating "fetching new videos" from "alerting the user" would give users much more control over their experience, keeping the feed fresh without cluttering the phone's notification UI.