-- Add a nullable thumbnail_filename column to ticket_attachments so an image
-- upload can store a separately-generated, resized preview alongside the
-- full-size original. NULL means no thumbnail exists (non-image, GD
-- unavailable at upload time, or an attachment uploaded before this existed)
-- and callers fall back to the full-size original.
--
-- scripts/cleanup_orphan_uploads.php's orphan lookup is updated in the same
-- change to also match thumbnail_filename, so generated thumbnails aren't
-- swept up as orphans.
--
-- Safe to re-run.

ALTER TABLE `ticket_attachments`
    ADD COLUMN IF NOT EXISTS `thumbnail_filename` varchar(255) DEFAULT NULL AFTER `filename`;