[b-studios]

Summary

Fix capture sets for handled capabilities during Core transformation.

A handler such as:

try {
  do tick()
} with tick {
  resume(())
  println("tick")
}

is translated to a transparent def:

reset { p =>
  def tick = new tick {
    ...
    println("tick")
  }

  do tick()
}

The source program types the handled body as capturing {tickCap}. After translation, tick is bound to a concrete handler that captures the prompt and io, so uses of tick must instead capture:

{p, io}

Previously, core retained the stale {tickCap} annotation.

The transformer now records a latent substitution when introducing a tracked Def binding:

tickCap ↦ {p, io}

This substitution is applied while translating subsequent capture sets and follows the existing withBindings scope.