mcp-smoke: CI smoke tests for MCP servers

CLI for CI pipelines. Boots any stdio MCP server like an agent would, checks the handshake, lists tools, validates each input schema and runs up to 20 example calls from a JSON file (expected text or error). Exit 0/1/2, human or JSON output. A crash or timeout never passes as an expected error, and it exits even when the server hides behind sh -c. TypeScript, MCP SDK, zod. 12 tests, CI on Node 22/24/26, v0.1.0.