context billing.handler

-- A service handler whose body carries a type error (adding an Int and a Bool),
-- while the addends type fine. The error surfaces in `check_context_declarations`
-- (handler bodies are typed there, not in `check_record`), exercising ADR 0094's
-- partial-type recording at that exit.
service charge {
  on call(cents: Int) -> Effect[Int] {
    let oops: Int = cents + true
    cents
  }
}
