-- Adds employee acknowledgment/sign-off to the appraisal workflow.
--
-- Professional performance-management practice closes the loop after HR
-- finalizes a review: the employee formally acknowledges having seen it
-- (an audit trail, and standard HR/legal practice), with room for their
-- own comment if they want to note a disagreement -- distinct from their
-- original self-review, which was written before anyone else's scores
-- existed.
--
-- Safe to run more than once.

ALTER TABLE `employee_appraisals`
    ADD COLUMN IF NOT EXISTS `acknowledged_at` DATETIME DEFAULT NULL AFTER `hr_reviewed_at`,
    ADD COLUMN IF NOT EXISTS `acknowledgment_comment` TEXT DEFAULT NULL AFTER `acknowledged_at`;