-- Aggregated like emails.
--
-- like_email_sent_at throttles the per-post like email: once an aggregated
-- "X and N others liked your post" email goes out, further likes within the
-- throttle window only update the in-app/push aggregate, not a fresh email.
ALTER TABLE notifications ADD COLUMN IF NOT EXISTS like_email_sent_at TIMESTAMPTZ;

-- Per-user opt-out for like emails (push + in-app are unaffected).
ALTER TABLE users ADD COLUMN IF NOT EXISTS like_emails_enabled BOOLEAN NOT NULL DEFAULT TRUE;