Keep the backlog focused on deferred TESTS; the related non-test gaps (model-allow-list, restriction-cache invalidation, server embed-recursion guard, collectPageEmbeds cycle guard, jest DI/lib0-ESM debt) are now tracked as issues #52-#56 and only linked from the backlog. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>