feat: allow all crons to be configurable via UI

[nitrosont]

Right now, the automatic video removal runs every night at 02:00 AM.
Due to energy prices in my country I don't run the server with Youtarr 24/7 and at 02:00 AM the server is switched off. Therefore my instance keeps on growing the list of available videos, which I would have to shrink (via deleting) manually.

I suggest a small input in the Settings / Auto Removal, so that the user can set the time of auto removal.

[BigFlubba]

Here are the current cron schedules that are running. I think the option to change the scheduling of things would be beneficial via cron, with an environment variable and in the UI.

[2026-09-16 15:18:39.718 +0000] INFO: Scheduled cron jobs initialized successfully

[2026-09-16 15:18:39.718 +0000] INFO:   - Automatic video cleanup: 2:00 AM daily

[2026-09-16 15:18:39.718 +0000] INFO:   - Session cleanup: 3:00 AM daily

[2026-09-16 15:18:39.718 +0000] INFO:   - Video metadata backfill: 3:30 AM daily

[2026-09-16 15:18:39.718 +0000] INFO:   - yt-dlp auto-update: 4:00 AM daily (when enabled)

[dialmaster]

What I think needs to be added is an entirely new section in Settings that allows all "cronned" jobs to have the time they run be configurable.
Perhaps adding a new DB table to store these settings?

[dialmaster]

What do you guys think about a UI that looks like this:
Settings -> Scheduling Page 1 (doesn't all fit into a single screenshot)

Settings -> Scheduling Page 2:

And then everywhere ELSE that HAD scheduling settings now links to the new page, eg:

[BigFlubba]

Looks good.

[nitrosont]

I agree, I think that a pretty good implementation. Thanks for the quick reaction / work!

[dialmaster]

This was merged to dev and will go out with the next release.