feat(go/plugin/anthropic): add Anthropic plugin

[hugoaguirre]

Environment

• Platform (select one):
  • [x] Anthropic API
  • [ ] AWS Bedrock
  • [ ] Google Vertex AI
  • [ ] Other:
• Claude CLI version: 1.0.30 (Claude Code)
• Operating System: Ubuntu 24.04.2 LTS (on WSL2)
• Terminal: Windows Terminal

Bug Description

The claude mcp add command fails when command-line header options are placed after the transport option argument, even though option order should not matter according to standard CLI conventions.

Steps to Reproduce

1. Run: claude mcp add --transport sse -H "Authorization: Bearer XXX" postman https://mcp.postman.com/sse
2. Observe the error

Expected Behavior

The command should work regardless of option order, as both commands have the same arguments and options.

Actual Behavior

Command fails with error: missing required argument 'name' when options are placed before the name argument.

Working command:

claude mcp add -H "Authorization: Bearer XXX" --transport sse postman https://mcp.postman.com/sse

Failing command:

claude mcp add --transport sse -H "Authorization: Bearer XXX" postman https://mcp.postman.com/sse

Additional Context

The help documentation for claude mcp add does not specify that option order matters, which makes this behavior unexpected. Standard CLI practice allows options to be placed anywhere in the command. Same problem with I use transport "http"