Constant DISK_HELP 

pub const DISK_HELP: &str = "Attach a raw virtio-blk disk to /dev/vda. \
     Accepts a human-readable size with a unit suffix (case-insensitive): \
     b, kib, mib, gib. IEC-only — SI variants (kb/mb/gb) are rejected to \
     keep the contract unambiguous. The size must be a positive whole \
     number of MiB (e.g. 256mib, 1gib). Omit to boot without a disk.";

Help text for the --disk <SIZE> shell flag, shared between cargo ktstr shell (src/bin/cargo_ktstr/cli.rs) and ktstr shell (src/bin/ktstr.rs) so a future tweak lands in one place. Mirrors the super::CPU_CAP_HELP pattern.