feat(calls): implement advanced multi-model ML noise suppression system

Implement a flexible, multi-model noise suppression pipeline for Element Call/LiveKit integration:

- ML Engines: Added support for RNNoise, Speex, DTLN, and DeepFilterNet 3 models.
- Pipeline Architecture: Implemented modular audio processing in lotus-denoise.js, supporting 'Series Suppression' (running browser-native NSNet2 before ML) and a hardware-style Noise Gate.
- UI & UX Enhancements:
  - Settings UI: Added model comparison chart with CPU/Quality metadata.
  - Tuning: Added Live Microphone Meter for calibrating Noise Gate thresholds.
  - Reporting: Added LotusToast system to alert users when ML suppression fails or falls back to raw input.
- Robustness & Quality:
  - Capture Fidelity: Removed forced 48kHz capture constraints to allow native-rate capture (solving static issues with high-end audio interfaces).
  - Performance: Added WASM SIMD detection with transparent fallback.
  - Capability Detection: Added browser feature detection to disable unsupported ML modes.
- Build Integration: Updated Vite config to self-host all model WASM/tflite assets in /denoise/ directory.

src/app/state/settings.ts

@@ -14,6 +14,7 @@ export type MessageSpacing = '0' | '100' | '200' | '300' | '400' | '500';
 //  - 'browser' : WebRTC built-in suppression (Element Call noiseSuppression param)
 //  - 'ml'      : client-side RNNoise ML suppression (Lotus denoise shim)
 export type NoiseSuppressionMode = 'off' | 'browser' | 'ml';
+export type DenoiseModelId = 'rnnoise' | 'speex' | 'dtln' | 'deepfilternet';
 export type ChatBackground =
   | 'none'
   | 'blueprint'
@@ -115,6 +116,10 @@ export interface Settings {
 
   cameraOnJoin: boolean;
   callNoiseSuppression: NoiseSuppressionMode;
+  callDenoiseModel: DenoiseModelId;
+  callDenoiseNativeNS: boolean;
+  callDenoiseGate: boolean;
+  callDenoiseGateThreshold: number;
   pttMode: boolean;
   pttKey: string;
 
@@ -205,6 +210,10 @@ const defaultSettings: Settings = {
 
   cameraOnJoin: false,
   callNoiseSuppression: 'browser',
+  callDenoiseModel: 'rnnoise',
+  callDenoiseNativeNS: true,
+  callDenoiseGate: false,
+  callDenoiseGateThreshold: -45,
   pttMode: false,
   pttKey: 'Space',