OAuth authentication fails with "username may be incorrect" error

[mimosa767]

I'm experiencing OAuth authentication failures when using the official Microsoft
Azure DevOps MCP Server (@azure-devops/mcp) with Claude Desktop on macOS.

Steps to Reproduce:

1. Configure Claude Desktop with the official Azure DevOps MCP server
2. Attempt to use any Azure DevOps tool
3. Browser opens for OAuth authentication
4. Enter credentials (stephen.penn@mabl.com)
5. Error: "This username may be incorrect"
6. After selecting account, get error: AADSTS900144: The request body must
   contain the following parameter: 'client_id'

Environment:

• OS: macOS
• Client: Claude Desktop
• MCP Server: @azure-devops/mcp (latest)
• Organization: https://dev.azure.com/mabldemo
• Account: stephen.penn@mabl.com

Additional Context:

• Can successfully authenticate to Azure DevOps via web browser
• Azure CLI (az login) authentication works perfectly
• Community alternative (@tiberriver256/mcp-server-azure-devops) with PAT
  authentication works correctly
• Suggests the OAuth implementation in the official server has a bug

Expected Behavior:
OAuth authentication should complete successfully and cache credentials

Actual Behavior:
OAuth fails with username error, then client_id parameter error