Marks a Microsoft To Do task as complete. It works through Apple Reminders, which syncs with To Do when the Microsoft account is added to Reminders, so the change appears in To Do after the next sync. Prefer task_id from todo_list_tasks. With title instead, it completes the one open task whose title contains that text (case-insensitive); if several match, it completes NONE and lists them with their task_id. Without list it searches every Reminders list, not only the To Do ones. Called without confirm it returns a preview; pass confirm=true to complete.