fix: add ffmpeg and chromaprint to Dockerfile for audio recognition

Dockerfile

@@ -2,6 +2,9 @@ FROM node:20-alpine
 
 WORKDIR /app
 
+# Install OS dependencies for audio processing
+RUN apk add --no-cache ffmpeg chromaprint
+
 # Install dependencies
 COPY server/package*.json ./server/
 RUN cd server && npm install --production