Why: Existing event and helper tests missed the SurfaceMeta to snapshot
reload path that blanked the app after the integration pointer regressed.
Evidence: New restore regressions fail on 1edd872 and pass on compatible
main; independent reviewer replays and real browser contract replay are
recorded in the Dev surface-black-screen-recovery task card.
Impact: Tests only; protects reload, partial failure, newer live revisions,
conversation switching, and two-page browser preview.
Refs: Frontend #68; Dev #454 and #452; Dev surface-black-screen-recovery
