[Feature Request] Fade/Crossfade setting

Is your feature request related to a problem? Please describe.

I use JMusicBot for my DnD campaign online for thematic music. When using some songs they sometimes just dont end nicely and it creates sudden jumps between songs when they jump from one song to another.

What is your ideal solution to the problem?

Being able to set a Crossfade/Fade time in which the playing song will reduce in volume from 100% to 0% and then stop playing and the next song in the queue will start playing ealier at 0% and go up to 100% by the time the playing song has faded to 0%.

How would this feature be used?

1. Set crossfade to an amount (1-10 seconds for example).
2. Play music in a queue.
3. The music fades out and in.

Additional Info

No response

Checklist

• I have checked the documentation to make sure this feature doesn't already exist
• I have searched for similar feature requests
• I have confirmed that my requests is not on the list of things that will not be added
• I am running the latest version of the bot:

Start by locating the music queue and audio playback entry points in the Java bot. Review how the current track ends and how the next queued track starts, then determine where a configurable 1–10 second fade or crossfade can be applied. Done means queued tracks transition smoothly according to the configured duration.