Add Docker setup: nginx frontend + backend compose

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

docker-compose.yml

@@ -0,0 +1,46 @@
+services:
+
+  # ── Frontend (nginx) ──────────────────────────────────────────────────────────
+  novasonic-frontend:
+    build: .
+    container_name: novasonic-frontend
+    restart: unless-stopped
+    ports:
+      - "8080:80"          # change left side to your desired host port
+    labels:
+      - "traefik.enable=true"
+      - "traefik.http.routers.novasonic.rule=Host(`novasonic.yourdomain.com`)"
+      - "traefik.http.routers.novasonic.entrypoints=websecure"
+      - "traefik.http.routers.novasonic.tls.certresolver=letsencrypt"
+
+  # ── Backend (yt-dlp download server) ─────────────────────────────────────────
+  novasonic-backend:
+    image: node:20-alpine
+    container_name: novasonic-backend
+    restart: unless-stopped
+    working_dir: /app
+    volumes:
+      - ./backend/novasonic-server.js:/app/novasonic-server.js:ro
+      - ${MUSIC_PATH:-/music}:/music   # your Navidrome music library
+    ports:
+      - "3700:3700"
+    environment:
+      - PORT=3700
+      - MUSIC_PATH=/music
+      - AUDIO_FMT=${AUDIO_FMT:-mp3}
+      - AUDIO_QUALITY=${AUDIO_QUALITY:-0}
+      - MAX_PARALLEL=${MAX_PARALLEL:-2}
+      - NAVIDROME_URL=${NAVIDROME_URL:-}
+      - NAVIDROME_USER=${NAVIDROME_USER:-}
+      - NAVIDROME_PASS=${NAVIDROME_PASS:-}
+    command: >
+      sh -c "
+        apk add --no-cache yt-dlp ffmpeg python3 &&
+        npm install express cors &&
+        node novasonic-server.js
+      "
+    labels:
+      - "traefik.enable=true"
+      - "traefik.http.routers.novasonic-api.rule=Host(`novasonic-api.yourdomain.com`)"
+      - "traefik.http.routers.novasonic-api.entrypoints=websecure"
+      - "traefik.http.routers.novasonic-api.tls.certresolver=letsencrypt"