feat: migra cliente web para áudio contínuo com VAD no backend

tests/js/pcm-worklet.test.mjs

@@ -0,0 +1,48 @@
+import assert from "node:assert/strict";
+import { readFileSync } from "node:fs";
+import { test } from "node:test";
+import vm from "node:vm";
+
+function processor() {
+  let Processor;
+  class Base {
+    constructor() {
+      this.port = { sent: [], postMessage(data) { this.sent.push(data); } };
+    }
+  }
+  vm.runInNewContext(readFileSync(new URL("../../src/voice_assistant/audio_gateway/web/pcm-worklet.js", import.meta.url), "utf8"), {
+    AudioWorkletProcessor: Base, sampleRate: 16000,
+    registerProcessor(name, constructor) { assert.equal(name, "pcm-input"); Processor = constructor; },
+  });
+  return new Processor();
+}
+
+test("negotiated capture emits complete little-endian PCM16 frames", () => {
+  const input = processor();
+  input.port.onmessage({ data: { type: "start", chunkSamples: 2 } });
+  input.process([[new Float32Array([-1, 0, 1])]]);
+  const chunk = input.port.sent[0];
+  assert.equal(chunk.type, "pcm");
+  assert.equal(chunk.buffer.byteLength, 4);
+  const samples = new DataView(chunk.buffer);
+  assert.equal(samples.getInt16(0, true), -32768);
+  assert.equal(samples.getInt16(2, true), 0);
+});
+
+test("capture continues across process callbacks until stop", () => {
+  const input = processor();
+  input.port.onmessage({ data: { type: "start", chunkSamples: 2 } });
+  input.process([[new Float32Array([0, 0, 0])]]);
+  input.process([[new Float32Array([0, 0])]]);
+  assert.equal(input.port.sent.filter((event) => event.type === "pcm").length, 2);
+  input.port.onmessage({ data: { type: "stop" } });
+  input.process([[new Float32Array([0, 0, 0])]]);
+  assert.equal(input.port.sent.length, 2);
+});
+
+test("invalid capture window reports an error", () => {
+  const input = processor();
+  input.port.onmessage({ data: { type: "start", chunkSamples: 0 } });
+  assert.equal(input.port.sent[0].type, "error");
+  assert.equal(input.capturing, false);
+});