Quiz share links replace the PIN copy with a public /share/{token} landing page; owners can enable/revoke without showing the full link. Moderated article/question comments with approval flow, bounds and rate limits. Educator AI article drafts/refine and private card generation with Celery job polling. Migrations f2a1c9d4e801 and g4b7e2f5a903. 50 backend and 85 frontend tests pass.
