Makes a cloned version independent of the version it was cloned from, in one transaction:

• the version names no source (source_version_id nil);
• none of its pages names the page it was copied from (MishkaDocument.Section's :detach_source), archived ones included, so deleting the old source's pages deletes none of these;
• its MishkaDocument.WorkspaceVersionLineage rows as the new version are deleted.

Each page keeps its section_lineage_id, the id its history across versions is read by, which no reference ties to a row. Every write is made with the action's actor, under the version's site. A version with no source is refused.

Once committed, "document:version:detached" is fired through MishkaInstaller.Event.Hook.call/3 with %{version_id: "…", source_version_id: "…", workspace_id: "…", site_id: "…", pages: 172} and meta: %{actor: actor, site_id: site_id}. What a plugin answers is not used.

update :detach do
  change MishkaDocument.Resources.Changes.DetachVersion
end