考虑增加指标埋点dashboard

- [ ] I have searched the [issues](https://github.com/apache/dubbo-admin/issues) of this repository and believe that this is not a duplicate.
- [ ] I have checked the [REAMDE](https://github.com/apache/dubbo-admin/blob/develop/README.md) of this repository and believe that this is not a duplicate.

### Is your feature request related to a problem? Please describe.
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目前监控指标可以通过普罗米修斯显示dubbo内部并没有存储或者显示这些指标项的方式，

### Describe the solution you'd like
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考虑增加一个导航链接到grafana或者内部嵌套iframe的形式，又或者dubbo admin主动查询存储指标的系统例如普罗米修斯来自行展示指标数据

### Describe alternatives you've considered
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### Additional context
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The issue names no files, tests, or entry points. Start by reviewing how Dubbo Admin currently exposes or links to Prometheus metrics, then compare the proposed Grafana link, embedded iframe, and internal querying approaches. Done would require a decided dashboard integration and a defined way to display the metrics.

Written by the indexing model from the issue text.