[sight] bug: AgentSight 节省的token计算有误

[zhangtaibo]

Component

sight

Bug Description

AgentSight 节省的token计算有误

Steps to Reproduce

1、启动cosh
2、输入Prompt ，“帮我安装一下Openclaw，不需要安装钉钉，API Key：sk-xxx，模型使用qwen3.6-max-preview”（sk需要输入正确的key）
3、登录AgentSight的web UI，查看节省
发现输出内容不正确

应该是
2116 - 241 = 1875，实际算出来却是15000

Expected Behavior

正确计算出节省的值

Environment

Alinux 4 ECS

Relevant Log Output

Additional Context

No response

[github-actions]

🔀 Issue Triage

This issue has been automatically assigned to @chengshuyi as the maintainer(s) of sight.

Maintainers, please review and triage this issue. Set a priority label and update the status as needed. Thanks! 🙏