debug: 添加 Flow Monitor 响应内容调试日志

- 在 ResponseTab 组件中添加 console.log
- 输出 response 对象、content 内容和长度
- 输出 expandedSections 状态
- 创建 issue-75 调查文档

相关 Issue: #75

src/components/flow-monitor/FlowDetail.tsx

@@ -785,6 +785,18 @@ function ResponseTab({
 }: ResponseTabProps) {
   const { response } = flow;
 
+  // 调试日志
+  console.log("[FlowDetail] ResponseTab - response:", response);
+  console.log("[FlowDetail] ResponseTab - content:", response?.content);
+  console.log(
+    "[FlowDetail] ResponseTab - content length:",
+    response?.content?.length,
+  );
+  console.log(
+    "[FlowDetail] ResponseTab - expandedSections:",
+    Array.from(expandedSections),
+  );
+
   if (!response) {
     return (
       <div className="rounded-lg border bg-muted/50 p-8 text-center text-muted-foreground">