Take the cross-cutting queries out of the model's base module

findPropertyUsages walks override sites, so Project.ts imported instance.ts
while instance.ts imported Project.ts – the repo's only value-level import
cycle. The queries now sit in usages.ts and Project.ts is a base type module
again. requireScene has had no caller since holderId replaced sceneId.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

src/editor/actions.ts

@@ -8,8 +8,9 @@ import { CompoundCommand } from '../core/commands/CompoundCommand';
 import { CreateContainerCommand } from '../core/commands/containerCommands';
 import { RemoveNodeCommand } from '../core/commands/graphCommands';
 import { RemoveSceneObjectsCommand } from '../core/commands/sceneObjectCommands';
-import { findAsset, findPropertyUsages, findUsages } from '../core/model/Project';
+import { findAsset } from '../core/model/Project';
 import { textureRefIds } from '../core/model/texture';
+import { findPropertyUsages, findUsages } from '../core/model/usages';
 import { Dialog } from '../ui';
 import { type EditorState, objectSelection } from './state';