feat: harden dedupe runtime and NAS deployment

docker-compose.yml

@@ -1,6 +1,6 @@
 services:
   am-deduper:
-    build: .
+    image: ${AM_DEDUPER_IMAGE:?Set AM_DEDUPER_IMAGE to the pushed Gitea registry image}
     container_name: am-deduper
     restart: unless-stopped
     command: ["watch", "/music/AllMusic"]
@@ -8,5 +8,6 @@ services:
       TZ: Asia/Shanghai
       PYTHONUNBUFFERED: "1"
     volumes:
-      - /your/nas/path/AllMusic:/music/AllMusic
+      - ${ALLMUSIC_PATH:?Set ALLMUSIC_PATH to the NAS AllMusic directory}:/music/AllMusic
+      - ${DEDUPE_DATA_PATH:?Set DEDUPE_DATA_PATH to the NAS app-data directory}:/data
     stop_grace_period: 30s