Summary:\n- added vendor-neutral MCP stdio server with marketplace, core CLI, and ethics tools\n- implemented plugin discovery across commands and skills\n- added Good/Bad/Ugly tests and Go module dependency updates
Exposes core CLI commands as MCP tools for AI agents.
This change introduces a Go-based MCP server that wraps the
existing core CLI commands (`go test`, `dev health`, `dev commit`),
providing structured JSON responses.
This allows AI agents to interact with the core CLI in a structured,
type-safe manner.
The implementation includes:
- A new Go HTTP server in `google/mcp/`
- Handlers for each of the core CLI commands
- Unit tests for the handlers with a mock `core` executable
- Documentation for the new MCP tools
- Integration with the `code` plugin via `plugin.json`
