RHL-005-fix(env): add local NAS volume configuration to docker-compose

docker-compose.local.yml

@@ -0,0 +1,5 @@
+services:
+  app:
+    volumes:
+      # Local mount: fixture NAS folder
+      - ./.local_nas:/mnt/niederlassungen:ro

docker-compose.yml

@@ -30,13 +30,14 @@ services:
     container_name: rhl-lieferscheine-app
     restart: unless-stopped
     env_file:
-      - .env.docker
+      - ${ENV_FILE:-.env.docker}
     depends_on:
       db:
         condition: service_healthy
     ports:
       - "3000:3000"
     volumes:
+      # Server mount: real NAS
       - /mnt/niederlassungen:/mnt/niederlassungen:ro
     command: sh -c "node scripts/validate-env.mjs && npm run start"