[Discovery] mcp/gitlab - GitLab API Integration

## Project Association

This issue tracks the `gitlab` MCP server in the core profile.

### Server Details
- **Name**: gitlab
- **Source**: https://github.com/modelcontextprotocol/servers/tree/main/src/gitlab
- **Docker Hub**: https://hub.docker.com/r/mcp/gitlab
- **Category**: git
- **Language**: TypeScript/Node.js

### Transport Status
- **Current**: stdio only (upstream)
- **Implementation**: HTTP-wrapped via supergateway
- **Docker Image**: `gitlab-mcp:http` (custom build)

### Tools Provided
- `search_repositories`: Search for GitLab projects
- `get_project`: Get project details
- `list_branches`: List branches in a project
- `get_file_contents`: Read file contents from a repository
- `create_or_update_file`: Create or update a file
- `push_files`: Push multiple files in a single commit
- `create_branch`: Create a new branch
- `create_merge_request`: Create a new merge request
- `list_merge_requests`: List merge requests
- `get_merge_request`: Get merge request details
- `merge_merge_request`: Merge a merge request
- `create_issue`: Create a new issue
- `list_issues`: List issues in a project
- `get_issue`: Get issue details
- `update_issue`: Update an existing issue
- `add_issue_comment`: Add comment to an issue
- `list_pipelines`: List CI/CD pipelines
- `get_pipeline`: Get pipeline details
- `trigger_pipeline`: Trigger a new pipeline

### Docker Status
- Official image: `mcp/gitlab`
- Custom wrapper: `gitlab.dockerfile`
- HADOLint: Not checked

### Notes
- Supports self-hosted GitLab via `GITLAB_API_URL`
- Comprehensive GitLab API coverage including CI/CD
- Requires `GITLAB_PERSONAL_ACCESS_TOKEN`

### Tracking
- [ ] Document all tools comprehensively
- [ ] HADOLint compliance check
- [ ] Test with self-hosted GitLab
- [ ] Consider Rust rewrite