fix(diagnostics): 诊断包恒报券商「已连接、1 个账户」，与是否登录无关 - #246

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. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/