-- P1-10: ReportPreference.lastSentAt for scheduled email reports
-- =========================================================
-- Same pattern as Theme B/C: this project uses `prisma db push`, so
-- this SQL documents the change for review + serves as the explicit
-- rollback record per CLAUDE.md.

-- ============================================================
-- UP
-- ============================================================

ALTER TABLE `ReportPreference`
  ADD COLUMN `lastSentAt` DATETIME(3) NULL;

-- ============================================================
-- DOWN
-- ============================================================
-- Safe: column is nullable, no FK, only read/written by the scheduler.

ALTER TABLE `ReportPreference`
  DROP COLUMN `lastSentAt`;