Two additions plus a viewer JSX rewire:
- legacy-system.tsx: <LegacySystem kind="..."> wrapper that renders its
children only when nodeRegistry.has(kind) is false. Lets one wrapper
cover all legacy systems for a kind (door has DoorSystem and
DoorAnimationSystem — both belong to 'door' so they yield together).
- registered-systems.tsx: <RegisteredSystems /> iterates the registry,
filters entries that contribute a system, sorts by system.priority
(default 5; e.g. wall mitering at 8 runs after door cuts at 3),
mounts each via React.lazy. Today empty registry = renders nothing.
- viewer/index.tsx: every existing per-kind system is wrapped in
LegacySystem. RegisteredSystems is mounted alongside.
With the registry empty (Phase 0), every LegacySystem passes through
unchanged and RegisteredSystems is a no-op — zero behavior change.
Once a kind registers in Phase 2+, its legacy systems yield and its
registry-contributed system runs in their place.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
