resend.listContacts returns paginated contact summaries, optionally for one segment.
automations/list-resend-customers.automation.ts
segmentId restricts results to one existing segment. limit accepts 1–100. You can’t combine the after and before cursors. Optional second argument { account } selects the binding.
Returns { data, hasMore, object: "list" }. Summaries contain id, email, nullable names, unsubscribed, and createdAt.