Fix: Use startup script to create .storage directories at runtime

- Changed from bind mount to named volume for .storage
- Added start.sh script that creates required directories before starting the app
- This prevents ENOENT errors when initializing admin user

docker-compose-prod.yml

@@ -12,7 +12,7 @@ services:
       - NODE_ENV=production
     restart: unless-stopped
     volumes:
-      - ./.storage:/app/.storage
+      - storage-data:/app/.storage
     networks:
       - stargirlnails-network
     healthcheck:
@@ -56,6 +56,8 @@ services:
 
 # Volumes für persistente Daten
 volumes:
+  storage-data:
+    driver: local
   certbot-certs:
     driver: local
   certbot-webroot: