...
create a copy into something that's not an Entity (e.g. into HTML) (a long term software project)
variation: Take a snapshot of the entity's JSON
change the give read-only ACL (don't move to new folder)
...
downside: only annotations and data file are currently versioned
Fundamental question:
Does the wiki actually need to be immutable? If not, what IS it that must be immutable, just the referenced file(s)?