NeonatoX/neonatox-live-boot ? reverse-engineered prompt

Build me a from scratch Linux live ISO builder that I can use to create a bootable system image with BIOS and UEFI support.

I want it to boot through GRUB, load a minimal initramfs, find a real root filesystem stored as squashfs, mount it read only, then create a writable live session with an overlay in RAM and hand off cleanly to systemd. It should also detect common boot devices like USB, SATA, NVMe, CD DVD, and IDE, and support early keyboard input for both USB and PS2 keyboards.

Please keep it simple and educational, with the boot process easy to follow and debug. I want clear build scripts, a small tool building step for the initramfs, and enough documentation so someone can understand what is happening at each stage. If you need to check current build details online, go ahead.