[BUG] HTTP MCP servers working in 2.1.140 and broken in 2.1.142.

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?

{
"mcpServers": {
"pixellab": {
"type": "http",
"url": "https://api.pixellab.ai/mcp",
"headers": {
"Authorization": "Bearer <token>"
}
}
}
}

What Should Happen?

Expected behaviour: On startup, Claude Code connects to the HTTP MCP server, fetches the tools list, and makes them available.

Actual behaviour: Startup log shows [MCP] --mcp-config servers running fully async (nonblocking) but no connection to the MCP URL is ever attempted. No error is logged. Tools never appear.

Error Messages/Logs

Steps to Reproduce

Steps to reproduce:

Add an HTTP MCP server to ~/.claude/settings.json as above
Reload the VS Code window
Observe no connection attempt in the Claude Code output log
Platform: Windows 11, VS Code extension v2.1.142
Regression from: v2.1.140 (confirmed working)

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

2.1.140

Claude Code Version

2.1.142

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

PowerShell

Additional Information

_No response_