Stuff in std and unsafe/dual constructors

In kernel, Deferred has unsafe and in constructors. Ref has those plus Ref.Make typeclass constructor. In std, semaphore has a dual-effect constructor (though it, probably wrongly, requires Async) while queues, CountDownLatch and CyclicBarrier don't support any of that. They all could, since their construction effect is some combination of ref + deferred allocations. (utilities creating Resources like Supervisor or Hotswap can't since they need to finalize in F).

There was an old discussion in #373 about why dual-type constructors are useful which still stands today. Arguably, we should be consistent everywhere as CE3 is a sort of a trend-setter in the ecosystem, and support those use cases or explicitly discard them and deprecate everywhere.

Start by comparing the existing constructors for kernel Deferred and Ref with the std semaphore implementation. Then inspect queues, CountDownLatch, and CyclicBarrier to determine which constructor variants they expose; done requires either consistent support for the applicable dual-effect and unsafe constructors or an explicit decision to deprecate that pattern.