*/
    public String regenerateQuery(final String userMessage, final String failedQuery, final String failureReason,
            final List<LlmMessage> history) {
        if (logger.isDebugEnabled()) {
            logger.debug("[LLM] Delegating regenerateQuery. llmType={}", getLlmType());
        }
        return getAvailableClient().regenerateQuery(userMessage, failedQuery, failureReason, history);
    }

     * @param history the conversation history
     * @return a new query string, or the userMessage if regeneration fails
     */
    String regenerateQuery(String userMessage, String failedQuery, String failureReason, List<LlmMessage> history);

    /**
     * Generates an answer using document content (streaming version for enhanced flow).
     *

    }

    // ========== regenerateQuery tests ==========

    @Test
    public void test_regenerateQuery_success_extractsNewQuery() {
        client.setChatResponse("{\"query\": \"Fess installation guide\", \"reasoning\": \"simplified keywords\"}");

        final String result = client.regenerateQuery("How do I install Fess on Docker?", "+\"Fess\" +Docker (installation OR setup)",

        final LlmChatRequest request = buildStreamingRequest(userMessage, context, history);

        return chatWithConcurrencyControl(request);
    }

    @Override
    public String regenerateQuery(final String userMessage, final String failedQuery, final String failureReason,
            final List<LlmMessage> history) {
        final long startTime = System.currentTimeMillis();
        if (logger.isDebugEnabled()) {

                    logger.info("[RAG] Primary search returned 0 results, regenerating query. originalQuery={}", query);
                    final String newQuery = llmClientManager.regenerateQuery(userMessage, query, "no_results", history);
                    if (StringUtil.isNotBlank(newQuery) && !newQuery.equals(query)) {
                        logger.info("[RAG] Regenerated query. newQuery={}", newQuery);