With --skip-errors, a file that failed to restore was verified anyway,
failed again because it was never written, and was added to the same
failure list as the restore failure. restore --verify then listed it
twice and called every entry a checksum mismatch.
Verification now skips the files that failed to restore and keeps its
own failures in a separate list, so failed restores and failed
verifications are reported apart, each path once. The restore still
exits non-zero. The tests cover a restore with skipped files where
nothing fails verification, and one where another restored file also
fails it.
Judgement call: the second test has its own trailing-byte file-system
wrapper; the one in restore_perms_test.go is in the internal test package.
Model: opus-5-5
sneak