Create a sprite asset from a texture's context menu

The sprite takes the whole image at its pixel size and the texture's name,
numbered like any other clash. CreateAssetCommand now accepts starting
properties; they go through the schema in execute, so an unknown key or a
bad value is refused before the project is touched, and one undo removes
the asset.

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

src/editor/panels/AssetPanel.ts

@@ -7,7 +7,9 @@ import {
   hasColorSwatch,
   isPlaceableType,
 } from '../../core/model/AssetTypes';
+import type { PropertyBag } from '../../core/model/Properties';
 import { findAsset } from '../../core/model/Project';
+import { spriteFromTexture } from '../../core/properties/aspect';
 import { assetDeviates } from '../../core/properties/deviation';
 import type { TextureStore } from '../../core/store/TextureStore';
 import { Button, ListView, Menu, type MenuItem, Panel, ScrollContainer, startDrag } from '../../ui';
@@ -77,8 +79,8 @@ export class AssetPanel extends Panel {
     this.list.select(s?.kind === 'asset' ? s.assetId : null, true);
   }
 
-  private createAsset(type: AssetType): void {
-    const command = new CreateAssetCommand(type, nextAssetName(this.state.project, ASSET_TYPE_LABELS[type]));
+  private createAsset(type: AssetType, name = ASSET_TYPE_LABELS[type], props: PropertyBag = {}): void {
+    const command = new CreateAssetCommand(type, nextAssetName(this.state.project, name), props);
     if (this.state.execute(command)) this.state.select({ kind: 'asset', assetId: command.asset.id });
   }
 
@@ -128,6 +130,12 @@ export class AssetPanel extends Panel {
         disabled: this.state.project.activeSceneId === id,
       });
     }
+    if (asset.type === 'texture') {
+      items.push({
+        label: 'Create sprite from texture',
+        onSelect: () => this.createAsset('sprite', asset.name, spriteFromTexture(this.state.project, id)),
+      });
+    }
     items.push({ label: 'Delete…', danger: true, onSelect: () => confirmDeleteAsset(this.state, id) });
     const menu = new Menu(items);
     menu.open(x, y);