Marketplace schema error: plugins[56] (semgrep) uses unsupported source type 'git-subdir'

Bug Description

The claude-plugins-official marketplace fails to load due to a schema validation error in marketplace.json at plugins[56] (semgrep entry).

Error Message

Failed to load marketplace "claude-plugins-official" from source (github): Failed to parse marketplace file at ...marketplace.json: Invalid schema: ...marketplace.json plugins.56.source: Invalid input

Root Cause

The semgrep plugin entry at index 56 uses "source": "git-subdir" which is not recognized by Claude Code's schema validator:

{
  "name": "semgrep",
  "description": "Semgrep catches security vulnerabilities in real-time and guides Claude to write secure code from the start.",
  "category": "security",
  "source": {
    "source": "git-subdir",
    "url": "https://github.com/semgrep/mcp-marketplace.git",
    "path": "plugin"
  },
  "homepage": "https://github.com/semgrep/mcp-marketplace.git"
}

Impact

This prevents all plugin installations from claude-plugins-official marketplace, not just the semgrep plugin. Any /plugin install <name>@claude-plugins-official command fails.

Expected Behavior

Either:

1. Claude Code's schema should support git-subdir source type, or
2. The semgrep plugin entry should use a supported source type

Environment

• Claude Code on Windows 11
• Claude Opus 4.6