test(utils): cover scheduledMessages + lotusDenoiseUtils; fix AudioWorklet detect

- scheduledMessages.test.ts (9): pins the MSC4140 request shape (PUT to the room
  send endpoint with the org.matrix.msc4140.delay query, POST cancel/restart to
  /delayed_events with the unstable prefix), the delay-floor math (Math.max(1000,
  round(sendAt-now)) — "now"/past targets still yield a valid >=1000ms delay),
  rounding, and url-encoding.
- lotusDenoiseUtils.test.ts (9): model-catalog data integrity + isMLDenoiseSupported
  feature detection across AudioContext/webkit/getUserMedia.
- Bug found + fixed: isMLDenoiseSupported used `!!AudioWorkletNode`, a bare global
  reference that throws ReferenceError (not returns false) on a browser with
  AudioContext but no AudioWorkletNode binding. Switched to `typeof` so the
  detection helper reports unsupported instead of throwing. Regression test proven
  to fail on the old code.

Suite now 545 tests (4th real bug caught by the prevention work).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/app/utils/lotusDenoiseUtils.test.ts

@@ -0,0 +1,108 @@
+import { test, beforeEach, afterEach } from 'node:test';
+import assert from 'node:assert/strict';
+
+import {
+  DENOISE_MODELS,
+  ML_DENOISE_REQUIREMENTS,
+  isMLDenoiseSupported,
+} from './lotusDenoiseUtils';
+
+// ── Model catalog (data integrity) ──────────────────────────────────────────
+
+test('DENOISE_MODELS lists the four expected models in order', () => {
+  assert.deepEqual(
+    DENOISE_MODELS.map((m) => m.id),
+    ['rnnoise', 'speex', 'dtln', 'deepfilternet'],
+  );
+});
+
+test('DENOISE_MODELS ids are unique', () => {
+  const ids = DENOISE_MODELS.map((m) => m.id);
+  assert.equal(new Set(ids).size, ids.length);
+});
+
+test('every model has non-empty display fields and valid rating enums', () => {
+  const transients = new Set(['Poor', 'Good', 'Excellent']);
+  const voice = new Set(['Moderate', 'High', 'Very High']);
+  for (const m of DENOISE_MODELS) {
+    for (const field of ['name', 'description', 'cpuUsage', 'binarySize'] as const) {
+      assert.ok(typeof m[field] === 'string' && m[field].length > 0, `${m.id}.${field} empty`);
+    }
+    assert.ok(transients.has(m.transients), `${m.id} bad transients: ${m.transients}`);
+    assert.ok(voice.has(m.voiceQuality), `${m.id} bad voiceQuality: ${m.voiceQuality}`);
+  }
+});
+
+test('ML_DENOISE_REQUIREMENTS is a non-empty list of strings', () => {
+  assert.ok(Array.isArray(ML_DENOISE_REQUIREMENTS) && ML_DENOISE_REQUIREMENTS.length > 0);
+  assert.ok(ML_DENOISE_REQUIREMENTS.every((r) => typeof r === 'string' && r.length > 0));
+});
+
+// ── isMLDenoiseSupported (feature detection) ────────────────────────────────
+
+const g = globalThis as Record<string, unknown>;
+const NAMES = ['window', 'navigator', 'AudioWorkletNode'] as const;
+let saved: Record<string, PropertyDescriptor | undefined>;
+
+const setGlobal = (name: string, value: unknown): void => {
+  Object.defineProperty(g, name, { value, configurable: true, writable: true });
+};
+const removeGlobal = (name: string): void => {
+  // Make a bare reference to `name` throw ReferenceError (simulate an absent
+  // global binding), as it would in a browser lacking the API entirely.
+  if (Object.getOwnPropertyDescriptor(g, name)) delete g[name];
+};
+
+const withMediaDevices = { mediaDevices: { getUserMedia: () => Promise.resolve() } };
+
+beforeEach(() => {
+  saved = {};
+  for (const n of NAMES) saved[n] = Object.getOwnPropertyDescriptor(g, n);
+});
+afterEach(() => {
+  for (const n of NAMES) {
+    const d = saved[n];
+    if (d) Object.defineProperty(g, n, d);
+    else if (Object.getOwnPropertyDescriptor(g, n)) delete g[n];
+  }
+});
+
+test('returns false when there is no window (non-browser)', () => {
+  setGlobal('window', undefined);
+  assert.equal(isMLDenoiseSupported(), false);
+});
+
+test('returns true when AudioContext, AudioWorklet and getUserMedia are present', () => {
+  setGlobal('window', { AudioContext: function AudioContext() {} });
+  setGlobal('AudioWorkletNode', function AudioWorkletNode() {});
+  setGlobal('navigator', withMediaDevices);
+  assert.equal(isMLDenoiseSupported(), true);
+});
+
+test('accepts the legacy webkitAudioContext prefix', () => {
+  setGlobal('window', { webkitAudioContext: function webkitAudioContext() {} });
+  setGlobal('AudioWorkletNode', function AudioWorkletNode() {});
+  setGlobal('navigator', withMediaDevices);
+  assert.equal(isMLDenoiseSupported(), true);
+});
+
+test('returns false when getUserMedia is unavailable', () => {
+  setGlobal('window', { AudioContext: function AudioContext() {} });
+  setGlobal('AudioWorkletNode', function AudioWorkletNode() {});
+  setGlobal('navigator', {}); // no mediaDevices
+  assert.equal(isMLDenoiseSupported(), false);
+});
+
+test('returns false (does NOT throw) when the AudioWorkletNode binding is absent', () => {
+  // Regression: a bare `!!AudioWorkletNode` threw ReferenceError on browsers
+  // with AudioContext but no AudioWorkletNode; a detection helper must report
+  // false, not throw.
+  setGlobal('window', { AudioContext: function AudioContext() {} });
+  setGlobal('navigator', withMediaDevices);
+  removeGlobal('AudioWorkletNode');
+  let result: boolean | undefined;
+  assert.doesNotThrow(() => {
+    result = isMLDenoiseSupported();
+  });
+  assert.equal(result, false);
+});