feat: persist production image storage

compose.production.yaml

@@ -37,6 +37,7 @@ services:
     environment:
       DATABASE_URL: postgresql://${POSTGRES_USER}:${POSTGRES_PASSWORD}@postgres:5432/${POSTGRES_DB}
       REDIS_URL: redis://redis:6379
+      IMAGE_STORAGE_ROOT: /var/lib/pokemon-inventory/images
     depends_on:
       postgres:
         condition: service_healthy
@@ -44,6 +45,8 @@ services:
         condition: service_healthy
     expose:
       - "3000"
+    volumes:
+      - image-storage:${IMAGE_STORAGE_VOLUME:-/var/lib/pokemon-inventory/images}
     healthcheck:
       test: ["CMD", "node", "-e", "fetch('http://127.0.0.1:3000/health').then((response) => process.exit(response.ok ? 0 : 1)).catch(() => process.exit(1))"]
       interval: 10s
@@ -61,11 +64,14 @@ services:
     environment:
       DATABASE_URL: postgresql://${POSTGRES_USER}:${POSTGRES_PASSWORD}@postgres:5432/${POSTGRES_DB}
       REDIS_URL: redis://redis:6379
+      IMAGE_STORAGE_ROOT: /var/lib/pokemon-inventory/images
     depends_on:
       postgres:
         condition: service_healthy
       redis:
         condition: service_healthy
+    volumes:
+      - image-storage:${IMAGE_STORAGE_VOLUME:-/var/lib/pokemon-inventory/images}
 
   web:
     image: ${WEB_IMAGE:-pokemon-inventory-web}:${IMAGE_TAG:-latest}
@@ -87,3 +93,4 @@ services:
 volumes:
   postgres-data:
   redis-data:
+  image-storage:

docs/DEPLOYMENT.md

@@ -45,6 +45,16 @@ worker images share the same Node workspace image; the web image builds the Vue
 application and serves it through Nginx with SPA fallback and internal `/api`
 proxying.
 
+API and worker share the persistent `image-storage` volume at
+`/var/lib/pokemon-inventory/images`. Set `IMAGE_STORAGE_VOLUME` to a NAS bind
+mount when deploying outside Docker-managed volumes, for example:
+
+```env
+IMAGE_STORAGE_VOLUME=/volume1/docker/pokemon-inventory/images
+```
+
+Include this directory in image-storage backups alongside PostgreSQL dumps.
+
 ## Tagged Releases And Rollback
 
 Use an immutable release tag for every deployment. The production Compose file