SmechOS netinst installer -- early beta

Early beta of the minimal netinst installer.

This is genuinely early -- it boots, partitions a disk, and walks through the
installer wizard (language, timezone, hardware detection, partitioning,
network, profile selection, microcode check, GRUB install), but the package
fetch steps depend on Smech-Labs/spk-repo-gun on GerritHub being populated,
and the underlying base userland still traces back to a host-copied
glibc/GNU system (see bin/MUSL_BOOTSTRAP_PLAN.md for the independent
musl+Clang bootstrap that will eventually replace that).

Tested: BIOS and UEFI boot in QEMU. Known working: GRUB El Torito boot,
parallel kernel module loading, the TUI installer wizard rendering and
navigation. Not yet verified: a full end-to-end install to a real disk on
real hardware -- treat this as a boot/UX preview, not a production installer
yet.

md5: 38201253c58e571ffe46bd6eadee89e0