[Enhancement] mobieusKnow: Revision history can only diff against current — no arbitrary version-to-version comparison

Area: mobieusKnow (audit p6) · Surface: /know/{slug}/history, /know/{slug}/history/{id} · Dimension: improve-existing · Severity: minor

MediaWiki, Confluence, and Notion let you pick any two revisions and see exactly what changed between them, which is essential for auditing a contested edit or understanding how an article evolved across several intermediate versions. mobieusKnow's diff is always anchored to 'current', so a moderator investigating 'what did revision #12 change relative to #10' (not relative to today) cannot do it. Given the diff engine already exists in the queue template, exposing a two-revision picker is a modest extension with real moderation value.

Evidence

historyRevision() loads exactly one historical revision and the single current approved revision for a side-by-side view (KnowledgeController.php:277-313: `$current = ... findById(current_revision_id)`). The history list (history.php:86-99) offers only 'View' (which diffs that revision vs current) and 'Restore'. There is no UI or controller path to select two arbitrary revisions and diff them; the diff renderer in queue.php is hard-wired to current-vs-proposed.

Suggested fix. Add a compare view (e.g. /know/{slug}/compare?from=A&to=B) reusing the existing unified-diff renderer, and let the history list select any two revisions (radio 'from'/'to' columns like MediaWiki) to drive it.

Filed by the automated tenant-app audit and adversarially evidence-verified. Status: verified. Open — not yet actioned.