fix(client): 会话总计改为 Σ 各轮成本（模型名回退最后一轮历史） - #15

The strategy configuration was canceled because "verify._22" failed

Process completed with exit code 2.

Cannot find name 'ChatNodesHook'.

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: actions/checkout@v4, actions/setup-node@v4. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/