Help: Music selection via Dropdown

Happy Easter everyone!

I have built an alarm clock automation which I control via a Shelly Wall Display.

I would now like to integrate a button on the wall display that gives me a selection of music tracks. These music files are in the MyMedia folder.
If I now select a piece of music, this music should be used by a Sonos speaker as an alarm clock.

The whole thing should work as dynamically as possible. This means that when I add a new piece of music to the MyMedia folder, it should also be available for selection in the dropdown.

At the moment I have implemented this in a very complicated way using various helpers, automations and browser mod. It works, but is a disaster when I want to add new music.

Have you already implemented something similar and do you have any ideas on how to make this as streamlined as possible?