Sleep Timer feature

[zord631]

It would be very useful to have a sleep timer when playing videos. This feature would allow users to set a specific time (for example: 10, 20, 30, or 60 minutes) after which the video automatically stops playing.
A timer would help people who watch videos before sleeping, study with long lectures, or simply want playback to stop after a certain period without needing to manually pause it.

This would improve convenience and help save battery.

[absurdlylongusername]

Duplicate of #2830.

Also please make feature requests as issues using the proper issue template and not as discussions, thank you.