-- Migration 021: the language an upload is transcribed as (tapir#61).
--
-- 'sv'   Swedish: the engines are sent language=sv. Every row before this migration was
--        transcribed that way (the request hard-coded it), so the default is true history.
-- 'auto' Other: the engine detects the language and the Swedish-only engine is not used.
--
-- A closed set held by the table as well as by the form and the request code, so a second
-- writer or a bug cannot store a value the engines are never meant to receive. The column
-- sits on the already-FORCE'd, RLS-scoped uploaded_transcripts, so the exact-set isolation
-- test is unaffected.
ALTER TABLE uploaded_transcripts
    ADD COLUMN language TEXT NOT NULL DEFAULT 'sv'
        CONSTRAINT uploaded_transcripts_language_check CHECK (language IN ('sv', 'auto'));