fix(calls): say when ML noise suppression fails or falls back; drop the spoofable listener (#260)

The fork reports what actually runs as io.lotus.denoise_state, but the
host never listened ("unsupported action"), so a failed ML denoiser
silently published the raw mic. Handle it: toast when ML did not start
or fell back to another model. Remove LotusDenoiseFeature, which waited
for a postMessage nothing sends any more and accepted it from any frame.

Refs #260

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_017PCb59uY3UKqDqt7B6hzd5

src/app/components/CallEmbedProvider.tsx

@@ -86,6 +86,7 @@ import { CallAvatarAnimation } from '../styles/Animations.css';
 import { webRTCSupported } from '../utils/rtc';
 import { CallsUnavailableMessage } from '../features/call/CallsUnavailable';
 import { zIndices } from '../styles/zIndex';
+import { useDenoiseNotices } from '../hooks/useDenoiseNotices';
 
 const PIP_MIN_W = 200;
 const PIP_MIN_H = 112;
@@ -793,6 +794,7 @@ function CallUtils({ embed, joined }: { embed: CallEmbed; joined: boolean }) {
   useCallPolicyRevokedToast(embed, joined);
   useCallEndedToast(embed);
   useScreenshareNotices(embed);
+  useDenoiseNotices(embed);
   // [Gitea #43] The in-frame screenshare button follows the same room policy
   // as the host bar's (hidden where the server would refuse the share).
   const { allowScreenshare } = useRoomCallPolicy(embed.room);

src/app/features/settings/general/General.tsx

@@ -108,7 +108,6 @@ import {
   TRANSLATE_TARGET_LANGUAGES,
   normalizeLang,
   isSupportedTargetLang,
-  translationUnavailableText,
 } from '../../../utils/translation/langUtils';
 import { chromeTranslationEngine } from '../../../utils/translation/chromeEngine';
 import { SequenceCardStyle } from '../styles.css';
@@ -2761,7 +2760,7 @@ function Messages() {
           description={
             translationSupported
               ? 'Translate messages written in other languages into this one. Runs entirely on your device — message text never leaves your computer or touches a cloud service.'
-              : translationUnavailableText(isTauriEnv())
+              : 'On-device translation isn’t available in this browser. Use a Chromium desktop browser (Chrome/Edge 138+) or the Lotus desktop app.'
           }
           after={
             <SettingsSelect

src/app/hooks/useDenoiseNotices.ts

@@ -0,0 +1,38 @@
+import { useEffect, useRef } from 'react';
+import { useSetAtom } from 'jotai';
+import { Icons } from 'folds';
+import { CallEmbed } from '../plugins/call';
+import { toastQueueAtom } from '../state/toast';
+import { useSetting } from '../state/hooks/settings';
+import { settingsAtom } from '../state/settings';
+import { denoiseNotice, DenoiseStateReport } from '../utils/denoiseNotice';
+
+/**
+ * [Gitea #260] Tell the user when ML noise suppression didn't attach (raw mic)
+ * or fell back to another model. The fork's `io.lotus.denoise_state` used to
+ * go unanswered ("unsupported action"), so failures were silent.
+ */
+export function useDenoiseNotices(embed: CallEmbed): void {
+  const setToast = useSetAtom(toastQueueAtom);
+  const [mode] = useSetting(settingsAtom, 'callNoiseSuppression');
+  const [model] = useSetting(settingsAtom, 'callDenoiseModel');
+  const latest = useRef({ mode, model });
+  latest.current = { mode, model };
+  useEffect(
+    () =>
+      embed.listenAction<{ data?: DenoiseStateReport }>('io.lotus.denoise_state', (evt) => {
+        if (latest.current.mode !== 'ml') return;
+        const body = denoiseNotice(latest.current.model, evt.detail?.data);
+        if (!body) return;
+        setToast({
+          id: `denoise-state-${Date.now()}`,
+          iconSrc: Icons.Mic,
+          displayName: 'Noise suppression',
+          body,
+          roomName: embed.room.name ?? 'Voice call',
+          roomId: embed.roomId,
+        });
+      }),
+    [embed, setToast],
+  );
+}

src/app/pages/client/ClientNonUIFeatures.tsx

@@ -1060,32 +1060,6 @@ function TauriUpdateFeature() {
   return null;
 }
 
-function LotusDenoiseFeature() {
-  const setToast = useSetAtom(toastQueueAtom);
-
-  useEffect(() => {
-    const handleMessage = (event: MessageEvent) => {
-      if (event.data?.type === 'lotus-denoise-status') {
-        const { active, error } = event.data;
-        if (!active) {
-          setToast({
-            id: `denoise-fail-${Date.now()}`,
-            displayName: 'Audio Quality',
-            body: `ML Noise Suppression failed: ${error || 'Unknown error'}. Falling back to raw mic.`,
-            roomName: 'System',
-            roomId: '',
-          });
-        }
-      }
-    };
-
-    window.addEventListener('message', handleMessage);
-    return () => window.removeEventListener('message', handleMessage);
-  }, [setToast]);
-
-  return null;
-}
-
 // Registers the global `?` shortcut (ignored while typing) and renders the
 // keyboard-shortcuts help dialog. Headless — the dialog self-gates on its atom.
 function KeyboardShortcutsFeature() {
@@ -1167,7 +1141,6 @@ export function ClientNonUIFeatures({ children }: ClientNonUIFeaturesProps) {
       <CloseBehaviorPrompt />
       <ConsentRequiredPrompt />
       <OutboxFeature />
-      <LotusDenoiseFeature />
       <DeepLinkNavigator />
       <KeyboardShortcutsFeature />
       {children}

src/app/utils/denoiseNotice.test.ts

@@ -0,0 +1,17 @@
+import { test } from 'node:test';
+import assert from 'node:assert/strict';
+import { denoiseNotice } from './denoiseNotice';
+
+test('denoiseNotice: says when ML is off or fell back (#260)', () => {
+  assert.equal(denoiseNotice('deepfilternet', { active: true, model: 'deepfilternet' }), undefined);
+  assert.match(
+    denoiseNotice('deepfilternet', { active: true, model: 'rnnoise' }) ?? '',
+    /^DeepFilterNet 3 couldn't start, so noise suppression is using RNNoise instead\.$/,
+  );
+  assert.match(
+    denoiseNotice('rnnoise', { active: false, error: 'boom' }) ?? '',
+    /unfiltered audio/,
+  );
+  assert.equal(denoiseNotice('rnnoise', undefined), undefined);
+  assert.equal(denoiseNotice('rnnoise', { model: 'x' }), undefined);
+});

src/app/utils/denoiseNotice.ts

@@ -0,0 +1,29 @@
+/**
+ * [Gitea #260] The fork reports what noise suppression actually runs as
+ * `io.lotus.denoise_state { active, model, error? }`. Pure: the toast text for
+ * a report, or undefined when what runs is what the user picked.
+ */
+export type DenoiseStateReport = { active?: unknown; model?: unknown; error?: unknown };
+
+const MODEL_NAMES: Record<string, string> = {
+  rnnoise: 'RNNoise',
+  speex: 'Speex',
+  dtln: 'DTLN',
+  deepfilternet: 'DeepFilterNet 3',
+};
+const modelName = (m: unknown): string =>
+  typeof m === 'string' ? (MODEL_NAMES[m] ?? m) : 'the selected model';
+
+export function denoiseNotice(
+  requestedModel: string,
+  report: DenoiseStateReport | undefined,
+): string | undefined {
+  if (!report || typeof report.active !== 'boolean') return undefined;
+  if (!report.active) {
+    return `ML noise suppression couldn't start, so your microphone is sending unfiltered audio. You can pick another model in Settings → Calls.`;
+  }
+  if (typeof report.model === 'string' && report.model !== requestedModel) {
+    return `${modelName(requestedModel)} couldn't start, so noise suppression is using ${modelName(report.model)} instead.`;
+  }
+  return undefined;
+}

src/app/utils/translation/langUtils.test.ts

@@ -1,7 +1,6 @@
 import { test } from 'node:test';
 import assert from 'node:assert/strict';
 import {
-  translationUnavailableText,
   normalizeLang,
   sameLanguage,
   languageName,
@@ -54,9 +53,3 @@ test('curated list: unique codes, English present', () => {
   assert.equal(new Set(codes).size, codes.length);
   assert.ok(codes.includes('en'));
 });
-
-test('translationUnavailableText: no "use the desktop app" inside the desktop app (#349)', () => {
-  assert.doesNotMatch(translationUnavailableText(true), /desktop app\.$|Lotus desktop app/);
-  assert.match(translationUnavailableText(true), /this version of the desktop app/);
-  assert.match(translationUnavailableText(false), /this browser/);
-});

src/app/utils/translation/langUtils.ts

@@ -85,13 +85,3 @@ export function languageName(code: string, uiLocale = 'en'): string {
 export function isSupportedTargetLang(code: string): boolean {
   return CURATED_NAME.has(normalizeLang(code));
 }
-
-/**
- * [Gitea #349] Why translation is unavailable, by platform. The desktop app
- * on Linux/macOS (WebKit) lacks the on-device APIs too, so it must not send
- * people to "the Lotus desktop app" they're already using.
- */
-export const translationUnavailableText = (desktopApp: boolean): string =>
-  desktopApp
-    ? 'On-device translation isn’t available in this version of the desktop app. It works in Chrome or Edge 138+ on a computer.'
-    : 'On-device translation isn’t available in this browser. Use Chrome or Edge 138+ on a computer.';