refactor(docker): make image-based the default compose, build variant is .dev

Less confusion: docker-compose.yml is now the default (pulls pre-built images)
and the build-on-host variant is docker-compose.dev.yml. Updated all references
(CLAUDE.md, README, .env.example, build-push-images.mjs, compose header).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

docker-compose.yml

@@ -1,75 +1,64 @@
+# Default (production) stack — PULLS pre-built images instead of building on the host.
+#
+#   docker compose pull
+#   docker compose up -d
+#
+# Build & push the images from your dev machine with:  npm run push-images
+# (see scripts/build-push-images.mjs). Set REGISTRY + TAG in .env (see .env.example).
+# To build on the host instead (dev), use docker-compose.dev.yml.
 services:
 
-  # ── Frontend (nginx) ──────────────────────────────────────────────────────────
   novasonic-frontend:
-    build: .
+    image: ${REGISTRY}/novasonic-frontend:${TAG:-latest}
+    pull_policy: always
     container_name: novasonic-frontend
     restart: unless-stopped
     ports:
-      - "8080:80"          # route this port through your reverse proxy
+      - "8080:80"
     environment:
-      - NAVIDROME_URL=${NAVIDROME_URL}   # pre-filled on the setup screen
-      - BACKEND_URL=${BACKEND_URL}       # pre-filled on the setup screen
-      - SCROBBLE_URL=${SCROBBLE_URL}     # play-log / stats service (setup screen)
+      - NAVIDROME_URL=${NAVIDROME_URL}
+      - BACKEND_URL=${BACKEND_URL}
+      - SCROBBLE_URL=${SCROBBLE_URL}
 
-  # ── Backend (yt-dlp download server) ─────────────────────────────────────────
   novasonic-backend:
-    image: node:22-slim
+    image: ${REGISTRY}/novasonic-backend:${TAG:-latest}
+    pull_policy: always
     container_name: novasonic-backend
     restart: unless-stopped
-    working_dir: /app
     volumes:
-      - ./backend:/app:ro                # mount entire backend dir (server + lib/)
       - ${MUSIC_PATH}:${MUSIC_PATH}      # exact path from .env, no remapping
-      - novasonic-data:/data             # writable data dir for overrides, state, etc.
+      - novasonic-data:/data
     ports:
-      - "3700:3700"                      # route this port through your reverse proxy
+      - "3700:3700"
     environment:
       - PORT=3700
-      - MUSIC_PATH=${MUSIC_PATH}         # same path inside the container
+      - MUSIC_PATH=${MUSIC_PATH}
       - DATA_PATH=/data
       - AUDIO_FMT=${AUDIO_FMT:-mp3}
       - AUDIO_QUALITY=${AUDIO_QUALITY:-0}
       - MAX_PARALLEL=${MAX_PARALLEL:-2}
       - DOWNLOAD_BACKEND=${DOWNLOAD_BACKEND:-ytdlp}
       - TICKETMASTER_API_KEY=${TICKETMASTER_API_KEY}
-      # Android APK download button — backend proxies a fixed Gitea release ("apk-latest"), same LAN.
-      # Optional: leave unset to use the local /data/novasonic.apk fallback instead.
-      - GITEA_URL=${GITEA_URL:-}                 # internal Gitea base, e.g. http://gitea:3000
-      - GITEA_REPO=${GITEA_REPO:-}               # owner/repo, e.g. Docker/NovaSonic
-      - GITEA_TOKEN=${GITEA_TOKEN:-}             # read token (only for a private repo)
+      # Android APK download button — backend proxies the fixed Gitea release ("apk-latest").
+      - GITEA_URL=${GITEA_URL:-}
+      - GITEA_REPO=${GITEA_REPO:-}
+      - GITEA_TOKEN=${GITEA_TOKEN:-}
       - GITEA_APK_TAG=${GITEA_APK_TAG:-apk-latest}
-    command: >
-      sh -c "
-        apt-get update && apt-get install -y --no-install-recommends python3 python3-pip ffmpeg curl git unzip && rm -rf /var/lib/apt/lists/* &&
-        pip install --break-system-packages -U --pre 'yt-dlp[default]' &&
-        curl -fsSL https://deno.land/install.sh | sh &&
-        pip install --break-system-packages spotapi 'git+https://github.com/TzurSoffer/spotify-downloader' &&
-        mkdir -p /deps && cd /deps && npm install express kuromoji &&
-        cd /app && PATH=/root/.deno/bin:$$PATH NODE_PATH=/deps/node_modules node novasonic-server.js
-      "
 
-  # ── Scrobble service (isolated timestamped play-log → stats + Wrapped) ────────
   novasonic-scrobble:
-    image: node:22-slim
+    image: ${REGISTRY}/novasonic-scrobble:${TAG:-latest}
+    pull_policy: always
     container_name: novasonic-scrobble
     restart: unless-stopped
-    working_dir: /app
     volumes:
-      - ./scrobble:/app:ro               # server code (read-only)
-      - novasonic-scrobble-data:/data    # own DB volume, isolated from downloads
+      - novasonic-scrobble-data:/data
     ports:
-      - "3710:3710"                      # route this port through your reverse proxy
+      - "3710:3710"
     environment:
       - PORT=3710
       - DATA_PATH=/data
       - NAVIDROME_URL=${NAVIDROME_URL}   # for ping.view auth verification
-    command: >
-      sh -c "
-        mkdir -p /deps && cd /deps && npm install express &&
-        cd /app && NODE_PATH=/deps/node_modules node --experimental-sqlite scrobble-server.js
-      "
 
 volumes:
-  novasonic-data:          # persistent storage for romaji overrides and app state
-  novasonic-scrobble-data: # persistent play-log DB (novasonic-plays.db)
+  novasonic-data:
+  novasonic-scrobble-data: