sasdallas/Ethereal ? reverse-engineered prompt

Build me a from scratch hobby operating system that boots into a polished desktop environment and feels like a real modern OS, not a Linux derivative.

I want a custom kernel with SMP, ACPI support, memory management, basic process and userspace support, and a window manager and desktop shell that can show a nice 1080p style UI. It should include working support for common hardware like USB, disk controllers, and a couple of network cards, plus a small libc and a set of userspace programs so it can actually run something useful.

Please set it up so it can build into a bootable ISO, ideally with a live boot path that loads the system into memory. If any external docs or current build details are needed, look them up online and use them. Keep it realistic for a hobby OS, but make it feel complete enough to boot, launch a desktop, and show basic apps and system services running.