-- A controller records, when it serves, how far the store's schema reaches in the build it is (novox/hq
-- issue 352): the highest migration it carries, by its build's version. A gate that fails the controller's
-- build puts the build before it back, and on 2026-10-09 that build was older than the migrations the
-- failed one had applied: it started, said it was behind its own row, and judged the next gate half-blind.
-- A put-back now reads this and keeps the current build when the one before it reaches less than the store.
create table controller_schema (
    build    text        primary key,
    reach    integer     not null,
    recorded timestamptz not null default now()
);