draft spatial grid

packages/core/src/index.ts

@@ -7,13 +7,21 @@ export {
   useRegistry,
 } from "./hooks/scene-registry/scene-registry";
 
+export { useSpatialQuery } from "./hooks/spatial-grid/use-spatial-query";
+export { initSpatialGridSync } from "./hooks/spatial-grid/spatial-grid-sync";
+
 // Systems
-export { LevelSystem } from "../../viewer/src/systems/level/level-system";
 export { WallSystem } from "./systems/wall/wall-system";
 
 // Events
 export { emitter, eventSuffixes } from "./events/bus";
-export type { ItemEvent, WallEvent, NodeEvent, GridEvent, EventSuffix } from "./events/bus";
+export type {
+  ItemEvent,
+  WallEvent,
+  NodeEvent,
+  GridEvent,
+  EventSuffix,
+} from "./events/bus";
 
 // Schema
 export * from "./schema";