[BUG] MCP HTTP transport: connectivity test fails because token is not included

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?

The MCP HTTP transport performs a "connectivity test" before making the actual MCP request, but this test doesn't include the Authorization header with the obtained OAuth token.

What Should Happen?

The token should be included in the connectivity test request.

Error Messages/Logs

Logs show:
  - Token obtained (951 chars)
  - "Testing basic HTTP connectivity to https://..."
  - "HTTP Connection failed after 16ms: Unauthorized"
  - "Redirection handling is disabled, skipping redirect"

Steps to Reproduce

1. Configure an MCP server with OAuth authentication
2. Complete the OAuth flow successfully
3. Claude Code gets "Auth result: AUTHORIZED" and has a valid token
4. But then "Testing basic HTTP connectivity" fails with 401

Claude Model

None

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.7

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

iTerm2

Additional Information

_No response_