Complete Cocos Creator port with level bundles, themes, and tooling.

Adds level prefabs, theme assets, audio, extensions, and deployment scripts for the Unity WebGL migration.

Co-authored-by: Cursor <cursoragent@cursor.com>

extensions/plugin-import-2x/creator/convertor/prefab.ts

@@ -0,0 +1,36 @@
+'use strict';
+import { ImporterBase } from '../common/base';
+import { MigrateManager } from "../components/MigrateManager";
+import { TrailModule } from "../components/TrailModule";
+
+function getOptimizationPolicy(value: string) {
+    switch (value) {
+        case 'AUTO':
+            return 0;
+        case 'SINGLE_INSTANCE':
+            return 1;
+        case 'MULTI_INSTANCE':
+            return 2;
+    }
+}
+
+export class PrefabImporter extends ImporterBase {
+    type: string = 'prefab';
+    async import(): Promise<boolean> {
+        this._3dMeta.ver = '1.1.26';
+        this._3dMeta.importer = "prefab";
+        const json2D = this.readJSONSync();
+        const json3D = new Array(json2D.length);
+        for (let i = 0; i < json2D.length; ++i) {
+            const obj = await MigrateManager.migrate(i, json2D, json3D);
+            if (obj.__type__ === 'cc.Prefab') {
+                obj.optimizationPolicy = getOptimizationPolicy(this._2dMeta.optimizationPolicy);
+                obj.asyncLoadAssets = this._2dMeta.asyncLoadAssets;
+            }
+        }
+        TrailModule.setParticleSystem(json3D);
+        this.ensureDefaultSprite2DFor3D(json3D);
+        this._2dTo3dSource = json3D;
+        return true;
+    }
+}