OpenClaw v2026.5.18 ships defineToolPlugin: typed plugin SDK with CLI tooling

OpenClaw's plugin ecosystem ships broken packages to production. The Brave plugin v2026.5.2 went live with only TypeScript source and no compiled dist/, crashing every gateway that installed it into an unrecoverable 1.2-second restart loop. Four separate GitHub issues filed for the same root cause. The new defineToolPlugin SDK (v2026.5.18) gives plugin authors a typed API, but there is no validation step between writing a plugin and publishing it to ClawHub where 44,000+ skills live. This tool runs a full lifecycle check in an isolated container: schema validation, build verification, dependency audit, gateway integration test, and provider registration smoke test. It catches the exact class of bugs that took down Brave search users.