Same fix as cd4302c for intelcpu: the bare sed against /etc/default/grub
missed systemd-boot and already-generated GRUB+BLS boot entries. Update
every kernel-argument surface idempotently, guarded by file existence:
/etc/kernel/cmdline, /etc/default/grub, and the options line of every
/boot/loader/entries/*.conf. Guard the nested=1 append as well.
- Move recipe-generator/ to cook/ for cleaner structure
- Fix ksflatten-relative path conversion to handle all %include paths
- Fix validation exit code to only fail on actual errors
- All recipes now generate and flatten successfully via make all
Lukas Greve