[BUG] Claude CoWork uses system node and not built in node to start MCP server

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

I haved installed a MCPB into my claude code

"server": {
    "type": "node",
    "entry_point": "dist/index.mjs",
    "mcp_config": {
      "command": "node",
      "args": [
        "${__dirname}/dist/index.mjs"
      ],
      "env": {
        .....
      }
    }
  },

when claude cowork starts this MCP it uses the system MCP and not the one bundle with claude desktop although the ui says otherwise

<img width="1272" height="622" alt="Image" src="https://github.com/user-attachments/assets/67aa8039-2389-4a68-8b71-96d1865d35f6" />

What Should Happen?

I expect the bundled node to be used

Error Messages/Logs

-

Steps to Reproduce

use a MCP that required a newer node on a machine with an older installed
=> mcp will fail although it would work if the node 24 in Claude Desktop would be used

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

Claude 1.1.7714 (3bd6f6) 2026-03-19T14:50:53.000Z

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Windows Terminal

Additional Information

_No response_