Implement an in-process broadcast event bus for resource mutations
(ADDED/MODIFIED/DELETED) with SSE watch endpoints on all list handlers,
following the Kubernetes watch protocol. Add the reddwarf-runtime crate
with a trait-based zone runtime abstraction targeting illumos zones,
including LX and custom reddwarf brand support, etherstub/direct VNIC
networking, ZFS dataset management, and a MockRuntime for testing on
non-illumos platforms.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
