[Feature Request] Add preload version

### Before you submit

- [x] I have searched the issue tracker for [open](https://github.com/Droid-ify/client/issues) and [closed](https://github.com/Droid-ify/client/issues?q=is%3Aissue+is%3Aclosed) issues that are similar to the feature request I want to file, without success.
- [x] I'm not requesting app support for a specific repo — that's up to repo maintainers
- [x] I understand this might not get built (Droid-ify is maintained by a single person)

### What's the problem?

Preload version

### What would help?

The Preload version of Droidify could be a good option.

This way, it can easily replace the original F-Droid app and be integrated into the system as a system app by ROM developers (or using Magisk/KernelSU modules).

In recent months, the Aurora Store added a “Preload” feature for easy integration, allowing apps to be installed silently in the background. Although Droidify can do this with root permissions, I think this will be a great feature. After all, the same functionality was available in the Aurora Store.

### Alternatives?

_No response_

### Anything else?

_No response_