ALTER TABLE payouts ADD COLUMN review_note TEXT;
CREATE TABLE notifications (
  id TEXT PRIMARY KEY,
  user_id TEXT NOT NULL REFERENCES users(id),
  event_type TEXT NOT NULL,
  source_id TEXT NOT NULL,
  message TEXT NOT NULL,
  target_path TEXT NOT NULL,
  read_at INTEGER,
  created_at INTEGER NOT NULL,
  UNIQUE(event_type,source_id)
);
CREATE INDEX idx_notifications_user_created ON notifications(user_id,created_at);