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-vm/test/unit/extension_music.js

@@ -0,0 +1,49 @@
+const test = require('tap').test;
+const Music = require('../../src/extensions/scratch3_music/index.js');
+
+const fakeRuntime = {
+    getTargetForStage: () => ({tempo: 60}),
+    on: () => {} // Stub out listener methods used in constructor.
+};
+
+const blocks = new Music(fakeRuntime);
+
+const util = {
+    stackFrame: Object.create(null),
+    target: {
+        audioPlayer: null
+    },
+    yield: () => null
+};
+
+test('playDrum uses 1-indexing and wrap clamps', t => {
+    // Stub playDrumNum
+    let playedDrum;
+    blocks._playDrumNum = (_util, drum) => (playedDrum = drum);
+
+    let args = {DRUM: 1};
+    blocks.playDrumForBeats(args, util);
+    t.strictEqual(playedDrum, 0);
+
+    args = {DRUM: blocks.DRUM_INFO.length + 1};
+    blocks.playDrumForBeats(args, util);
+    t.strictEqual(playedDrum, 0);
+
+    t.end();
+});
+
+test('setInstrument uses 1-indexing and wrap clamps', t => {
+    // Stub getMusicState
+    const state = {currentInstrument: 0};
+    blocks._getMusicState = () => state;
+
+    let args = {INSTRUMENT: 1};
+    blocks.setInstrument(args, util);
+    t.strictEqual(state.currentInstrument, 0);
+
+    args = {INSTRUMENT: blocks.INSTRUMENT_INFO.length + 1};
+    blocks.setInstrument(args, util);
+    t.strictEqual(state.currentInstrument, 0);
+
+    t.end();
+});