digestOf static method
The digest stamped on a snapshot record: sha256 over the canonical
(sorted-key) JSON of snapshot. save stamps it; the restore path
recomputes it over whatever is actually on disk, so an edited or
planted checkpoint file is rejected instead of restored.
Implementation
static String digestOf(Map<String, Object?> snapshot) =>
sha256.convert(utf8.encode(jsonEncode(_sorted(snapshot)))).toString();