readonly.json writable: False
valid.json      the course proof pack (from the ae22f3b run, holding 3 receipts)
forged.json     lesson 4 txid swapped and the hash re-sealed (harness/forge_pack.py.txt)
tampered.json   valid.json with the memo text edited and the sha256 left as it was
invalid-notjson.json  the bytes "not json {"
invalid-empty.json    the JSON object {}
readonly.json   a copy of valid.json with the read-only attribute set, so the --record write fails
missing.json    does not exist
folder/a.json   a copy of valid.json
