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/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}