-- finished_at is "the owner marked this Series finished" (#157): epoch ms,
-- zero means not finished, and it doubles as the undo (write zero). The poll
-- gate reads it — a Series is polled only while finished_at = 0 — never a
-- bookmark's status.
ALTER TABLE series ADD COLUMN finished_at bigint NOT NULL DEFAULT 0;

-- Column first, seed second, flip third — the order is load-bearing: a seed
-- that ran after the flip would read the buckets it just destroyed, declare
-- nothing finished, and silently resume polling on Series nobody chose to
-- resume. The seed mirrors the pre-cutover due gate exactly: a Series stays
-- polled while any bookmark is outside the finished bucket, so a Series whose
-- every bookmark sits in it is stamped, one click from being read again
-- afterwards. The stamp is the only memory of the bucket the flip is about to
-- erase.
UPDATE series s SET finished_at = (EXTRACT(EPOCH FROM now()) * 1000)::bigint
 WHERE EXISTS (SELECT 1 FROM bookmarks b
                WHERE b.site = s.site AND b.series_id = s.series_id)
   AND NOT EXISTS (SELECT 1 FROM bookmarks b
                    WHERE b.site = s.site AND b.series_id = s.series_id
                      AND b.status <> 'finished');

-- The Lifecycle bucket is gone; a finished bookmark is an archived one. The
-- flip must come after the seed, which still reads the bucket.
UPDATE bookmarks SET status = 'archived' WHERE status = 'finished';