Test os-install scripts (Arch, Chimera) via VM-based automation

[kergoth]

Context

The script/{distro}/os-install scripts handle the lowest level of the setup progression: booting a live ISO and installing the initial rootfs. These exist for distros without a comprehensive installer or where we want to skip one:

• script/arch/os-install — Arch Linux installation from live ISO
• script/chimera/os-install — Chimera Linux installation from live ISO

These scripts cannot be tested in containers since they need a bootable environment with disk partitioning, filesystem creation, and chroot operations. Currently they're only validated by manual installation, making regressions hard to catch.

Testing Approach

Needs a VM that can:

1. Boot a distro's live ISO
2. Attach a virtual disk
3. Run the os-install script non-interactively (or with scripted input)
4. Verify the resulting installation boots and reaches a usable state
5. Optionally continue with setup-root → setup-full to validate the full progression

Considerations

• Non-interactive operation: os-install scripts may have interactive prompts (disk selection, partitioning choices) that need to be handled
• Disk simulation: Need virtual disks for partitioning/formatting without risk to real hardware
• Boot verification: After install, the VM should be able to reboot into the installed system
• Snapshot/restore: Ability to reset to a clean state between test runs

Related Issues

• Investigate VM-based testing tooling for dotfiles validation #58 — VM-based testing tooling investigation
• Investigate non-Linux platform testing (macOS, Windows, FreeBSD) #57 — Non-Linux platform testing