Clamp effective_min to DISK_TWIST_MAX in randomize_disk() so gen_range never receives an empty range. Also guard all params.disks.len() - 1 subtractions with saturating_sub to prevent overflow if disks is empty.
Clamp effective_min to DISK_TWIST_MAX in randomize_disk() so gen_range never receives an empty range. Also guard all params.disks.len() - 1 subtractions with saturating_sub to prevent overflow if disks is empty.