docs(fixed):更新Arabica Sprint开发文档指南中mermaid示意图语法与GitLink平台不兼容的代码

Signed-off-by: gzkoala <guohao@gitconomy.org>

projects/arabica/docs/design/arabica-sprint2-development-specification.md

@@ -1024,7 +1024,7 @@ graph TD
     A[收到 prompts/list 请求] --> B[调用 listFrameworks]
     B --> C[获取框架元信息列表]
     C --> D[遍历框架，转换为 prompts 格式]
-    D --> E["返回 { prompts: [...] }"]
+    D --> E[返回 prompts]
 ```
 
 2. **调用序列图**