feat: initial commit — VoiceCoach real-time voice coaching pipeline

Services: Pipecat agent (LiveKit + Claude + Whisper STT + Piper TTS),
SpeechBrain analysis service, Piper TTS service, web client (nginx).
Includes LiveKit server config and docker-compose orchestration.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

web-client/Dockerfile

@@ -0,0 +1,8 @@
+FROM nginx:alpine
+
+COPY index.html /usr/share/nginx/html/
+COPY app.js /usr/share/nginx/html/
+COPY style.css /usr/share/nginx/html/
+COPY nginx.conf /etc/nginx/conf.d/default.conf
+
+EXPOSE 80