`prune`, `snapshot purge`, `snapshot remove` and `database delete`
printed "Cancelled" or "Aborted." and exited 0 when the prompt was
answered no or stdin ended. They now return vaultik.ErrNotConfirmed,
so the command reports "deletion not confirmed" and exits 1.
`database delete` reads its answer from the command's stdin instead of
os.Stdin, so a test can supply it.
Model: opus-5-5
