Validate that the enabled special page satisfies the non-product-facing readiness criteria from the preamble that M1 is responsible for: the cross-wiki read path works end-to-end under realistic Test Wikipedia traffic, cold-path fallback is exercised and behaves correctly, the banner renders correctly on desktop and mobile, cross-wiki tab links resolve via the abstract: interwiki prefix, and the individual-action logs/traces added in M0 observability show the expected per-request structure when sampled.

Product-facing readiness criteria (sysop opt-in via CommunityConfiguration, mainspace surfacing, search) are M2's responsibility and are explicitly not gated by this bullet.