-- One row per person. Keyed by their Discord user ID; carries the SHA-256 of
-- their userscript token and when they were created. Hashed because a token
-- in the database is a token anyone with the database can replay; SHA-256 is
-- enough because the tokens are high-entropy random values with nothing to
-- brute-force. No one can register yet, so this table holds exactly the one
-- owner row the seed creates at startup (see Store.Open).
CREATE TABLE readers (
  id           bigserial PRIMARY KEY,
  discord_id   text NOT NULL UNIQUE,
  token_sha256 bytea NOT NULL UNIQUE,
  created_at   timestamptz NOT NULL DEFAULT now()
);

-- Every bookmark now belongs to a reader. Added nullable: rows created before
-- this migration have no owner yet — 0004 attaches them to the seeded owner
-- before NOT NULL and the composite key land.
ALTER TABLE bookmarks ADD COLUMN reader_id bigint;