feat(call): denoise asset smoke check at ML-tier call start

HEAD-checks the copied denoise worklet/wasm/model assets for the selected model
and console.warns a single line listing anything missing — a silent asset skew
between the EC fork's expectations and vite's copied files would otherwise
disable noise suppression with no signal. Fire-and-forget; never blocks call
setup.

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

src/app/plugins/call/CallEmbed.ts

@@ -27,6 +27,7 @@ import {
 } from './types';
 import { CallControl } from './CallControl';
 import { CallControlState } from './CallControlState';
+import { verifyDenoiseAssets } from './denoiseSmokeCheck';
 
 // Maximum time to wait for the embedded Element Call iframe to progress from
 // initial load to a ready/joined state. If it hasn't by then, we assume the
@@ -205,6 +206,12 @@ export class CallEmbed {
       params.append('lotusModel', denoiseModel);
       params.append('lotusGate', denoiseGate.toString());
       params.append('lotusGateThreshold', denoiseGateThreshold.toString());
+
+      // [lotus] Fire-and-forget: confirm the fork's ML-denoise assets are
+      // actually served under public/element-call/denoise/ (they're copied by
+      // vite.config.js at build time). Warns once if the copy step regressed;
+      // never blocks call start.
+      verifyDenoiseAssets(denoiseModel).catch(() => undefined);
     }
 
     if (CallEmbed.startingCall(intent)) {

src/app/plugins/call/denoiseSmokeCheck.ts

@@ -0,0 +1,63 @@
+import { trimTrailingSlash } from '../../utils/common';
+
+// Denoise assets copied into public/element-call/denoise/ by vite.config.js's
+// lotusDenoise() plugin. The filenames here MUST match what that plugin writes
+// (and what the fork's TrackProcessor fetches at runtime). Grouped per model so
+// the smoke-check only probes what the active call will actually load.
+const DENOISE_ASSETS: Record<string, readonly string[]> = {
+  rnnoise: ['rnnoiseWorklet.js', 'rnnoise.wasm', 'rnnoise_simd.wasm'],
+  speex: ['speexWorklet.js', 'speex.wasm'],
+  dtln: ['workadventure/audio-worklet.js'],
+  deepfilternet: [
+    'deepfilternet/index.esm.js',
+    'deepfilternet/v2/pkg/df_bg.wasm',
+    'deepfilternet/v2/models/DeepFilterNet3_onnx.tar.gz',
+  ],
+};
+
+// The noise-gate worklet is a shared asset the build ships for every model
+// (loaded when the gate is enabled), so probe it regardless of the model.
+const SHARED_ASSETS: readonly string[] = ['noiseGateWorklet.js'];
+
+/**
+ * Fire-and-forget smoke-check for the ML-denoise asset contract.
+ *
+ * The fork's in-source denoiser (lotusDenoiseSource) loads its worklet/wasm/ESM
+ * from `public/element-call/denoise/` at runtime; if the build's asset copy
+ * step regressed, those fetches 404 and denoise silently degrades to a raw mic.
+ * This HEAD-fetches the critical assets for the selected model and emits a
+ * single console.warn listing any that are missing. No UI, no throw — purely a
+ * developer/operator breadcrumb.
+ *
+ * @param model the selected denoise model (defaults to rnnoise)
+ * @returns true if every probed asset responded OK, false otherwise
+ */
+export async function verifyDenoiseAssets(model = 'rnnoise'): Promise<boolean> {
+  const base = new URL(
+    `${trimTrailingSlash(import.meta.env.BASE_URL)}/public/element-call/denoise/`,
+    window.location.origin,
+  );
+  const names = [...(DENOISE_ASSETS[model] ?? DENOISE_ASSETS.rnnoise), ...SHARED_ASSETS];
+
+  const results = await Promise.all(
+    names.map(async (name): Promise<string | null> => {
+      try {
+        const res = await fetch(new URL(name, base).href, { method: 'HEAD' });
+        return res.ok ? null : name;
+      } catch {
+        return name;
+      }
+    }),
+  );
+
+  const missing = results.filter((n): n is string => n !== null);
+  if (missing.length > 0) {
+    console.warn(
+      `[lotus-denoise] ML denoise assets missing under ${base.href} (model="${model}"): ${missing.join(
+        ', ',
+      )} — the in-source denoiser will fall back to a raw mic. Check vite.config.js lotusDenoise().`,
+    );
+    return false;
+  }
+  return true;
+}