perf(llm): 优化知识库更新功能和 HTTP 请求配置

- 更新知识库时增加了 HTTP 请求配置，提高请求超时时间和并发处理能力
- 设置默认的 Accept头为 application/json，提高与外部服务的兼容性

yudao-module-llm/yudao-module-llm-biz/src/main/java/cn/iocoder/yudao/module/llm/service/knowledgebase/KnowledgeBaseServiceImpl.java

@@ -17,6 +17,7 @@ import cn.iocoder.yudao.module.llm.dal.mysql.knowledgedocuments.KnowledgeDocumen
 import cn.iocoder.yudao.module.llm.service.application.ApplicationService;
 import cn.iocoder.yudao.module.llm.service.async.AsyncKnowledgeBase;
 import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper;
+import kong.unirest.Unirest;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.stereotype.Service;
 import org.springframework.validation.annotation.Validated;
@@ -71,6 +72,13 @@ public class KnowledgeBaseServiceImpl implements KnowledgeBaseService {
         KnowledgeBaseDO updateObj = BeanUtils.toBean(updateReqVO, KnowledgeBaseDO.class);
         knowledgeBaseMapper.updateById(updateObj);
 
+        Unirest.config()
+                .socketTimeout(50000)
+                .connectTimeout(100000)
+                .concurrency(10, 5)
+                .setDefaultHeader("Accept", "application/json")
+        ;
+
         // 4. 处理附表（知识文档）数据
         if (!CollectionUtils.isAnyEmpty(updateReqVO.getKnowledgeDocuments())) {
             // 4.1 获取需要保留的文档 ID