Enhancement: Add a tokens per second field in the model selection hover

Currently, I can see the cost, context length, reasoning levels info when I hover over a model name in the model selector. I would love to be able to also see the speed of the model specially when I am running simple tasks, I want to choose the fastest model out there.

从模型选择器的悬停 UI 开始，追踪成本、上下文长度和推理级别信息的提供方式。确定 tokens-per-second 数据的可用来源，将其与现有字段一起显示，并验证将鼠标悬停在模型上时会显示速度信息。

由索引模型根据 Issue 内容生成。