updateCheckItem changes one checklist item through its containing card.
automations/complete-trello-check-item.automation.ts
card and itemId are required. Provide at least one of name, state: "complete" | "incomplete", position, dueAt, clearDue, dueReminder, or memberId. Dates accept Date or an ISO timestamp with offset; reminders are integers of at least -1. clearDue and dueAt are mutually exclusive. Optional account defaults to the project binding.
Returns the updated TrelloCheckItem. Trello requires the card because checklist-item updates are addressed through the card resource.