feat: long task

Author: niuweili

flashduty/en/2. RUM/2. Applications/4. Analysis Dashboard.md

@@ -31,7 +31,7 @@ The overview module focuses on the core metrics of your application across multi
 The performance analysis module focuses on full-chain monitoring of application loading and interaction experience, including:
 
 - **Page Performance**: Monitor trends and sample distribution of core page loading metrics such as FCP, LCP, CLS, and FCP.
-- **Long Tasks**: Events that block the browser's main thread for more than 50 milliseconds.
+- **Long Tasks**: A [long animation frame](https://developer.chrome.com/docs/web-platform/long-animation-frames#long-frames-api)  is when a rendering update is delayed beyond 50 milliseconds.
 - **XHR and Fetch Requests**: Analyze the loading performance of XHR and Fetch interfaces to locate slow interfaces.
 - **Static Resources**: Analyze the loading time of static resources to identify performance bottlenecks during application loading.
 

flashduty/zh/2. RUM/2. 应用管理/4. 分析看板.md

@@ -31,7 +31,7 @@ Flashduty RUM 分析看板提供了开箱即用的可视化仪表板，自动采
 性能分析模块专注于应用加载与交互体验的全链路监控，主要内容包括：
 
 - **页面性能**：监控 FCP、LCP、CLS、FCP 等页面加载核心指标的趋势与样本分布。
-- **长任务**：阻塞浏览器主线程超过 50 毫秒的事件。
+- **长任务**：[长动画帧](https://developer.chrome.com/docs/web-platform/long-animation-frames#long-frames-api)渲染更新延迟超过 50 毫秒的情况。
 - **XHR 和 Fetch 请求**：分析 XHR 和 Fetch 接口的加载性能，定位慢接口。
 - **静态资源**：分析静态资源的加载耗时，定位应用加载时的性能瓶颈。