-- Vendor, not provider.
--
-- novox/hq ADR 0050 renames the licence's vendor field from `provider` to `vendor`. "provider" is
-- already the word the inventory uses for *which node answers a brokered provision*; reusing it for
-- *which company sells this licence* would collide two unrelated facts on one word. The consolidated
-- schema (0001) now creates the column as `vendor`; this migration carries an existing database the
-- same distance.
--
-- **Guarded so it is a no-op on a fresh database.** A database created after 0001 was updated
-- already has `vendor` and no `provider` column, and PostgreSQL has no `RENAME COLUMN IF EXISTS` --
-- so the rename is wrapped in an explicit existence check. On a database that predates the rename
-- the `provider` column is present and is renamed; on a fresh one nothing is done, and both end with
-- exactly the same schema.
do $$
begin
    if exists (
        select 1 from information_schema.columns
        where table_name = 'licence' and column_name = 'provider'
    ) then
        alter table licence rename column provider to vendor;
    end if;
end $$;