Fix some script bugs

types/asset/assetbatch.d.ts

@@ -31,7 +31,12 @@ interface AssetBatch {
   /** `true` if any entry is in an `ERROR` state. */
   readonly hasError: boolean;
   /**
-   * Blocks until every entry is loaded.
+   * Returns a Promise that resolves when all entries have loaded, or rejects
+   * if any entry errors. Use with `await`.
+   */
+  loaded(): Promise<void>;
+  /**
+   * Blocks (spin-waits) until every entry is loaded.
    * Returns `this` for chaining.
    * @throws If any entry fails to load.
    */

types/asset/assetentry.d.ts

@@ -33,7 +33,12 @@ interface AssetEntry {
   /** Event proxy — subscribe up to 4 callbacks for when loading fails. */
   readonly onError: AssetEventProxy;
   /**
-   * Blocks until the entry reaches `LOADED` (or `ERROR`).
+   * Returns a Promise that resolves when the entry is loaded, or rejects on
+   * error. Use with `await`.
+   */
+  loaded(): Promise<void>;
+  /**
+   * Blocks (spin-waits) until the entry reaches `LOADED` (or `ERROR`).
    * Returns `this` for chaining.
    * @throws If the load fails.
    */

types/asset/asseteventproxy.d.ts

@@ -0,0 +1,23 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ *
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+/**
+ * An event proxy with up to 4 subscribable callback slots (indices 0–3).
+ * Assign a function to subscribe; assign `null` to unsubscribe.
+ *
+ * @example
+ * assets.onLoaded[0] = () => { Console.print('all loaded'); };
+ * assets.onLoaded[0] = null; // unsubscribe
+ */
+interface AssetEventProxy {
+  0: (() => void) | null;
+  1: (() => void) | null;
+  2: (() => void) | null;
+  3: (() => void) | null;
+  /** Number of available slots (always 4). */
+  readonly length: number;
+}