Spawn node: place assets at runtime into the play copy, Spawner demo behavior

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

src/editor/panels/Inspector.ts

@@ -12,6 +12,7 @@ import {
 import { AddVariableCommand, nextVariableName, RemoveVariableCommand, RenameVariableCommand } from '../../core/commands/variableCommands';
 import { edgesInto, inlineInputDef, inlineInputs, nodeDef } from '../../core/graph';
 import type { Asset, BehaviorAsset, SceneAsset } from '../../core/model/Asset';
+import { isPlaceableType } from '../../core/model/AssetTypes';
 import { isSelfOrAncestor, treeOrder } from '../../core/model/hierarchy';
 import type { Position, PropertyValue } from '../../core/model/Properties';
 import { findAsset, findScene, findSceneObject } from '../../core/model/Project';
@@ -395,11 +396,18 @@ export class Inspector extends Panel {
     this.body.add(new Button('Delete node', { variant: 'danger', onClick: () => this.state.execute(new RemoveNodeCommand(assetId, nodeId)) }));
   }
 
-  /** Variable params pick from the asset's variables; everything else is used as declared. */
+  /**
+   * Variable params pick from the asset's variables, asset params (Spawn) from the project's
+   * placeable assets; everything else is used as declared.
+   */
   private resolveParamDef(param: PropertyDef, asset: Asset): PropertyDef {
     if (param.kind === 'enum' && param.key === 'variable' && asset.type === 'behavior') {
       return { ...param, options: asset.variables.map((v) => ({ value: v.key, label: v.key })) };
     }
+    if (param.kind === 'enum' && param.key === 'asset') {
+      const options = this.state.project.assets.filter((a) => isPlaceableType(a.type)).map((a) => ({ value: a.id, label: `${a.name} (${a.type})` }));
+      return { ...param, options };
+    }
     return param;
   }