GitLab plugin: support configurable base URL for self-hosted instances

Preflight Checklist

• [x] I have searched existing requests and this feature hasn't been requested yet
• [x] This is a single feature request (not multiple features)

Problem Statement

The GitLab plugin currently hardcodes https://gitlab.com/api/v4/mcp as the MCP server URL. This means users with self-hosted GitLab instances (GitLab CE/EE) cannot use the plugin without manually patching the plugin cache file — which gets overwritten on every plugin update.

Proposed Solution

Support a configurable base URL via pluginConfigs in settings.json:

  "pluginConfigs": {
    "gitlab@claude-plugins-official": {                                                                                                                     
      "options": {                     
        "gitlabUrl": "https://git.example.com"                                                                                                              
      }                                                  
    }  
  }  

The plugin's .mcp.json would then resolve the URL from this config value instead of hardcoding gitlab.com.

Alternative Solutions

Workaround (Current)

Manually edit ~/.claude/plugins/cache/claude-plugins-official/gitlab/unknown/.mcp.json and replace the URL — but this reverts on every plugin update.

Priority

High - Significant impact on productivity

Feature Category

MCP server integration

Use Case Example

_No response_

Additional Context

• Claude Code with GitLab plugin (gitlab@claude-plugins-official)
• Self-hosted GitLab CE/EE