Disk Health SMART Summary

Summarise SMART attributes for every block device and flag any drive whose reallocated sector count or pending sector count is non-zero.

Constraints

• Iterate over /dev/sd* devices.
• Parse attributes 5 (reallocated) and 197 (pending).
• Print device, both counts and an OK or WARN verdict.
• Skip devices smartctl cannot read, with a note.
• Exit 1 if any device warns.
• Do not require root to fail gracefully.