fix: /history 只列真人轮次（按 source.kind 过滤合成注入）+ 冷路径优先模型面 readSurface - #6

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/