clickhouse-migrate-test-support-0.1.0.0: test/fixtures/kansoku/original/0011_events_raw_identifiers.sql
-- EP-18 M1: persist the identifiers map (kind -> value) on raw events.
-- The ClickHaskell wire carries a JSON-object String; '{}' keeps old rows
-- valid for server-side JSON extraction without rewriting existing parts.
ALTER TABLE analytics.events_raw
ADD COLUMN IF NOT EXISTS identifiers String DEFAULT '{}' AFTER context;