chore(addon/aikefu): 修复stream_chat_demo.html FetchAPI 获得完整的回复

src/addon/aikefu/docs/stream_chat_demo.html

@@ -317,8 +317,7 @@
                     buffer += decoder.decode(value, { stream: true });
                     
                     // 处理接收到的数据
-                    processStreamData(buffer, (newData) => {
-                        buffer = newData;
+                    buffer = processStreamData(buffer, (newData) => {
                         if (newData) {
                             // 更新 AI 消息
                             aiMessage += newData;
@@ -328,7 +327,7 @@
                 }
 
                 // 处理剩余数据
-                processStreamData(buffer, (newData) => {
+                buffer = processStreamData(buffer, (newData) => {
                     if (newData) {
                         aiMessage += newData;
                         updateAIMessage(aiMessage);