check-host-deps (and the build scripts themselves) reported build
dependencies as missing even though the packages were installed. Several
tools — debootstrap, sgdisk, losetup, partprobe, mkfs.vfat, grub-install —
live in /usr/sbin or /sbin, which non-root users and CI runners often
don't have on PATH, so `command -v` failed.
- common.sh now prepends /usr/local/sbin:/usr/sbin:/sbin to PATH, so every
script finds these tools no matter who invokes the build.
- check-host-deps now distinguishes "package not installed" from "installed
but not on PATH" via dpkg-query, so the message tells you exactly what is
wrong instead of a misleading "missing package".
90f1e4cc77