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);