Extracts the assistant reply from a completed tidyllm_research_job returned
by openai_deep_research(.background = TRUE).
openai_fetch_research(.job, .max_tries = 3)An updated LLMMessage with the research reply appended.
A tidyllm_research_job object. If not yet completed, polls once via
openai_check_research() and errors if still incomplete.
Maximum retries per HTTP request (default: 3).