✨(frontend) enhance noise reduction with BBBA audio processing pipeline

Replace the basic RNN noise processor with a more advanced audio
pipeline powered by Big Blue Better Audio (BBBA), a project
supported by the Prototype Fund.

The new WASM-based pipeline introduced by @falkTX and
@trummerschlunk adds:
- voice isolation
- high-pass filtering
- spectral balancing
- multiband compression
- low-pass filtering

This significantly improves overall audio quality and speech
clarity.

More information about the pipeline is available on the
trummerschlunk/BigBlueBetterAudio repo.

Voice isolation still relies on RNNNoise, a widely used deep
learning-based denoising model. Audio quality could be further
improved in the future if DeepFilterNet becomes usable directly
in the browser.

Their code has been released in an NPM package under GPL license.

src/frontend/package.json

@@ -17,6 +17,7 @@
   "dependencies": {
     "@fontsource-variable/atkinson-hyperlegible-next": "5.2.6",
     "@fontsource-variable/lexend": "5.2.11",
+    "@libreaudio/la-call": "0.1.4",
     "@fontsource/opendyslexic": "5.2.5",
     "@livekit/components-react": "2.9.21",
     "@livekit/components-styles": "1.2.0",