Version comparison — highlight changes between published versions

Description: When reviewing a Knowby, it would be useful to be able to compare the current version against a previously published version, with changes highlighted. This would help reviewers and approvers quickly understand what has changed without having to read the entire document.

Proposed behaviour: A "Compare versions" option on a published Knowby that allows the user to select any two published versions and see additions, removals, or edits highlighted inline.

Initial scope: To keep this manageable, comparison could initially be limited to the current version against one other selected published version.

Use case: Quality managers and approvers in regulated environments need to understand what changed between revisions — particularly relevant for document control workflows.