Initial commit of 001code-html Scratch frontend project.

Includes scratch-gui, scratch-vm, scratch-blocks, scratch-render, scratch-l10n, and deployment config.

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

scratch-gui/src/lib/tw-extension-gui-api.js

@@ -0,0 +1,41 @@
+import LazyScratchBlocks from './tw-lazy-scratch-blocks';
+import AddonHooks from '../addons/hooks';
+
+/**
+ * Implements Scratch.gui API for unsandboxed extensions.
+ * @param {any} Scratch window.Scratch, mutated in place.
+ */
+const implementGuiAPI = Scratch => {
+    Scratch.gui = {
+        /**
+         * Lazily get the internal ScratchBlocks object when it becomes available. It may never be
+         * available if, for example, the user never enters the editor.
+         *
+         * You should not assume that ScratchBlocks becoming available means the user is actually
+         * in the editor or that a workspace has been created already.
+         *
+         * @returns {Promise<any>} Promise that may eventually resolve to ScratchBlocks
+         */
+        getBlockly: () => {
+            if (AddonHooks.blockly) {
+                return Promise.resolve(AddonHooks.blockly);
+            }
+            return new Promise(resolve => {
+                AddonHooks.blocklyCallbacks.push(() => resolve(AddonHooks.blockly));
+            });
+        },
+
+        /**
+         * Get the internal ScratchBlocks object as soon as possible. This lets you access it even
+         * if the user never enters the editor.
+         *
+         * This method is VERY SLOW and will cause A LOT OF CPU AND NETWORK ACTIVITY because it
+         * downloads and evaluates all of scratch-blocks, a multi-megabyte JavaScript bundle.
+         *
+         * @returns {Promise<any>} Promise that will resolve to ScratchBlocks.
+         */
+        getBlocklyEagerly: () => LazyScratchBlocks.load()
+    };
+};
+
+export default implementGuiAPI;