"Xcode Cloud is a continuous integration and delivery service built into Xcode and designed expressly for Apple developers."
This is a (presumably well-integrated) alternative to CircleCI. There's nothing about this particular product that would make it even remotely relevant for a middle school programming curriculum.
At any rate, what you're asking for already exists — Swift Playgrounds has been around for years, it's specifically tailored for learners, is kid-friendly, and already lets you take the whole journey from your first line of code to publishing on the App Store.