add potentially-effectful cleanup actions to an outfit's `dress`

[horrible-little-slime]

This will probably need to be modified to better match kas's vision, but this is just a bullet point proposal for how to set things up.

[Kasekopf]

I like this idea for attaching some prep/cleanup to an outfit. I think beforeDress and afterDress also need corresponding optional properties on OutfitSpec, and also .clone() and .spec() should be updated.

[Kasekopf]

Thanks!