Microtask
The end of the current task: next waits for it, then goes on before any timer, frame or later task,
the same on every platform. The Clock starts its loop there, and an Environment can hold work to it,
as @wardic/dom does its end-of-task holds.
import * as Microtask from "@wardic/core/Microtask"
yield* Microtask.next // the rest of this task's work has runVariables
next
const next: Effect.Effect<void>;Waits for the end of the current task, then goes on, inside that microtask: before any timer, frame or later task. It needs nothing, no Clock, no scheduler. Interrupting it before then cancels it.