Add Option to Choose FX Sounds for Songs

It would be awesome if Songer had a built-in way to add FX sounds and effects to songs - things like fireworks, impacts, transitions, ambient textures, etc.

Right now I've tried tagging with things like [Fireworks], [Fireworks FX], and other effect names, but there's no reliable way to control what FX get added.

A dropdown menu or dedicated FX panel where you could browse and apply sound effects would make it much easier to add polish to tracks without having to layer them in manually.