Core AI

Docs: search the current Core AI documentation at https://developer.apple.com/documentation. APIs are new, so do not answer from memory.

• Building needs the Metal Toolchain.
• NDArray views are read-only by default. Use mutableView(as:) for writes.
• Ahead-of-time compilation removes most but not all on-device specialization, and only targets Apple Intelligence devices. --preferred-compute overrides the default compute units.