Build uses --bootloaders "grub-efi,syslinux" so live-build reads
config/bootloaders/grub-efi/ for the UEFI GRUB config. The directory
was incorrectly named grub-pc, causing live-build to ignore our custom
grub.cfg and generate a default one (missing toram, GSP-off entries).
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>