[Feature]: Download scheduler

[crashedthecymbal]

Prerequisites

• [x] I have searched existing issues and discussions to ensure this feature hasn't been requested before
• [x] I have read the feature request guidelines in the README
• [x] I understand that MeTube development relies on community contributions and the maintainer is not likely to implement this feature
• [x] I have considered if this feature should be implemented in yt-dlp instead of MeTube (if so, please report to yt-dlp repository)

Feature Description

Some links are only available within a certain time frame. It would be great to add the link, but start the download later at an given time.

Implementation Plan

No, I'm requesting this feature but cannot implement it

Additional Context

No response