feat(dbChain): 新增上下文内容

src/main/java/cn/com/poc/agent_application/aggregate/impl/AgentApplicationServiceImpl.java

@@ -1182,7 +1182,7 @@ public class AgentApplicationServiceImpl implements AgentApplicationService {
                 context.append(message.getRole()).append(":").append(message.getContent()).append(StringUtils.LF);
             }
         }
-        return context.toString();
+        return "";
     }
 
     /**