-- Manual date-edit rework (ticket #115).
--
-- POST /image/exif/date now writes the new-contract triple
-- (date_utc, camera_offset_minutes, date_taken_tz_source = 'manual')
-- alongside the legacy (date_taken, date_taken_source) pair. Reverting an
-- override must restore the resolver's new-contract triple as well as the
-- legacy pair, so image_exif snapshots the pre-override new-contract
-- columns next to the existing legacy snapshot pair
-- (original_date_taken / original_date_taken_source).

ALTER TABLE image_exif ADD COLUMN original_date_utc BIGINT;
ALTER TABLE image_exif ADD COLUMN original_camera_offset_minutes INTEGER;
ALTER TABLE image_exif ADD COLUMN original_date_taken_tz_source TEXT;