Install engine

There is no universal “install any Linux ISO from outside a live environment” standard. Thumbelina will wrap per-family tools:

Preferred: rootfs / bootstrap

  • Debian/Ubuntu: debootstrap / rootfs tarballs

  • Arch: bootstrap tarball / pacstrap-equivalent unpack

  • Fedora: dnf --installroot or container root layers

  • Alpine / others: OCI or minirootfs

Result: unpack into a named Btrfs subvolume, then regenerate GRUB.

Fallback: unattended installer in a helper VM

Attach the USB (or its Btrfs partition) to headless QEMU/Hyper-V and feed:

  • Ubuntu autoinstall

  • Debian preseed

  • Fedora/RHEL kickstart

  • Arch archinstall config

Host matrix

  • Linux: native partition + btrfs-progs + bootstrap

  • Windows / macOS: helper Linux VM with the raw disk attached (Btrfs is not writable in Explorer)

GUI and CLI share the same library API for plan → confirm → execute.