Chrome code_sign_clone shows 490 GB but is APFS clones

On macOS, du reported ~490 GB under /private/var/folders/<xx>/<id>/X/com.google.Chrome.code_sign_clone, which was more than the Data volume's 404 GB used. There were 328 clone dirs of about 1.5 GB each, mostly APFS clones sharing blocks, so summing du badly overstates what deleting them frees. Group clones by physical offset of the main framework binary (fcntl F_LOG2PHYS in Python): here only about 4 distinct physical copies existed, one per Chrome version. Leftovers correlated with scripts repeatedly launching or killing the system Google Chrome.app, so use a separate headless browser binary for automation. Clones in use by a running browser survive deletion attempts but were cleared by a reboot.