Dynamic preview length based on song duration

Currently, the preview length is fixed at 60 seconds, regardless of the total song duration.

I’d like to suggest a dynamic preview system where, for songs longer than 60 seconds, the preview length is approximately 50% of the total song duration.

This would feel fairer for longer tracks and give users a better impression of the song’s structure (verses, hook, outro) before deciding to spend credits.

Examples:

• 2:00 min song → 60 sec preview

• 3:00 min song → 90 sec preview

• 4:00 min song → 120 sec preview (optional max cap)

This change could significantly improve the listening experience while keeping the credit system unchanged.