ci: cover shared runtime and tools regressions

[rwang23]

Summary / 摘要

• Include runtime/ and tools/ in the Node syntax scan.
• Run the existing tools/*.test.mjs suite in pull-request CI and the release gate.

Type / 类型

• Bug fix / 缺陷修复
• Feature / 新功能
• Docs / 文档
• Theme / CSS / visual / 主题或视觉
• Scripts / install / restore / 脚本或安装恢复
• Chore / 杂项

Platform / 平台

• macOS
• Windows
• Both / 双平台
• Docs / repo only / 仅文档或仓库元数据

Self-check / 自测

Docs-only / 仅文档

• Links and wording reviewed / 已检查链接与表述

User-facing / 用户可见变更

• N/A — no user-facing change / 无用户可见变更

Security / 安全

• Does not modify official Codex install / asar / signatures / 未修改官方安装与签名
• Does not silently write API Base URL or keys / 未静默写入 API Base URL 或 Key
• CDP remains loopback-oriented (127.0.0.1) where applicable / CDP 仍仅本机回环（如适用）

Notes / 补充

The workflow only syntax-checked macOS and Windows source, so canonical runtime
and maintenance tools could regress without the same gate. This patch adds the
existing directories and test suite; it does not introduce a new dependency.

Validated on Windows at main@611c101 with:

• Node syntax checks for every .mjs/.js file under runtime, tools, macos, and windows — passed
• node --test tools/*.test.mjs — passed
• node --test windows/tests/*.test.mjs — passed
• powershell.exe -NoProfile -ExecutionPolicy RemoteSigned -File windows/tests/run-tests.ps1 — passed
• Python YAML parsing of both workflow files — passed
• git diff --check — passed

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Tracking issue / 追踪 Issue

Closes #300