}

    /**
     * Creates a testable CoordinatorHelper that overrides tryStartOperation(name,data,retries)
     * to simulate "create always fails" (no OpenSearch), preserving the retry/cleanup dispatch logic.
     */
    private CoordinatorHelper createRetryTestHelper(final AtomicBoolean cleanupCalled, final AtomicInteger cleanupRetries,

 *
 * Orchestrates the multi-phase RAG workflow including session management,
 * document search, and delegation to LlmClientManager for LLM operations.
 * Prompt construction and LLM-specific logic is handled by LlmClient implementations.
 *
 * @author FessProject
 */
public class ChatClient {

    private static final Logger logger = LogManager.getLogger(ChatClient.class);