feat: add core domain model foundations

core/index.ts

@@ -0,0 +1,18 @@
+export type { Artboard } from "./artboard";
+export type { Asset } from "./asset";
+export type { BaseLayer, LayerClippingMask } from "./base-layer";
+export type { ImageDocument } from "./document";
+export type {
+  Angle,
+  Bounds,
+  CoordinateSpace,
+  Mat2D,
+  Rect,
+  Size,
+  Transform,
+  Vec2D,
+} from "./geometry";
+export type { ArtboardId, AssetId, DocumentId, LayerId } from "./id";
+export type { ImageLayer } from "./image-layer";
+export type { Layer } from "./layer";
+export type { LayerGroup } from "./layer-group";