Create configuration to migrate john-endesktop from Arch Linux to NixOS while
maintaining existing ZFS pools (media JBOD and swarmvols mirror) and NFS
exports for k3s cluster.
Configuration includes:
- ZFS support with automatic pool import
- NFS server exporting both pools to 10.0.0.0/24
- Correct ZFS hostid (007f0101) to resolve hostid warnings
- Btrfs root filesystem on nvme0n1p5 (810GB)
- Comprehensive migration plan with rollback procedures
The migration is designed to be safe with Arch Linux remaining bootable
as a fallback until NixOS is verified stable.