For each patient, creates a thread, sets its voice phone number, sends patient's data as JSON input, and starts a phone call. If a patient already has an existing thread linked, it is reused.

Args: input: Request body containing patient_ids and eligibility_flow_id. authorization: API key for authentication. { "patient_ids": ["patient-123", "patient-456"], "eligibility_flow_id": "eligibility-flow-123" } Returns: list: List of dictionaries with thread_id, call, and callee for each patient.