netlify deploy with pnpm install on Windows breaks Astro site SSR

Describe the bug

when using pnpm install and netlify deploy viewing site shows error decoding lambda response: error decoding lambda response: unexpected end of JSON input

this works fine though when using npm install or building though CI from a github push

Steps to reproduce

• create a basic astro site with SSR (output: "server")
• pnpm install (--shamefully-hoist doesn't work either here)
• netlify build
• netlify deploy

Configuration

[build]
  command = "pnpm run build"
  publish = "dist"

Environment

  System:
    OS: Windows 11 10.0.26100
    CPU: (12) x64 Intel(R) Core(TM) i7-8700K CPU @ 3.70GHz
    Memory: 6.77 GB / 15.91 GB
  Binaries:
    Node: 22.13.1 - ~\AppData\Local\fnm_multishells\21492_1738563419315\node.EXE
    Yarn: 1.22.22 - ~\AppData\Local\pnpm\yarn.CMD
    npm: 10.9.2 - ~\AppData\Local\fnm_multishells\21492_1738563419315\npm.CMD
    pnpm: 9.15.4 - ~\AppData\Local\fnm_multishells\21492_1738563419315\pnpm.CMD

Reproduce the issue on Windows 11 with an Astro SSR site using pnpm install, netlify build, and netlify deploy, then compare the result with npm install and a GitHub-push build. Start by tracing the CLI's build and deploy handling for pnpm-based projects; done means the deployed SSR site loads without the lambda JSON decoding error.