ADR-0087 exemption (already-registered): That entry, unreleased and shipping in the same release, already prescribes this change's TO for every customization of an installed package: write it into the base's paired `<base>.custom` with `PUT /api/v1/meta/<type>/<name>?package=<base>.custom` and the `overrides` declaration (its replacement), because the customization lives there (its reason, ADR-0146 D1, D2, D11). Its surface and reason now name the commit doors as further addresses of the rollback it closes (text only, no new id). No stored row is rewritten or moved, so `objectstack migrate meta` has nothing new to do.