Effect testEffect and it.live

Always use testEffect(...) for Effect services, layers, context, and scoped resources; use it.live(...) for filesystem, Git, HTTP, sockets, processes, locks, and real time. Prefer actual implementations, explicit layers, scoped fixtures, and finalizers over mocks or ad hoc runtimes because ownership and cleanup remain visible. Avoid globalThis unless unavoidable and never duplicate implementation logic in tests. Run tests only from the owning package.