Create a page_version

Creates a page version. Pass exactly one of:

• page_id — snapshots the page's current title and body as a new version, optionally labelled via name.
• restored_from_version_id — creates a new version whose snapshot is copied from an earlier version, marking a restore point. The page's live body is not changed by this call.

Editing a page records versions automatically (edits within two minutes merge into one); use this endpoint for named snapshots and restore points.