feat: Add combined Dockerfile for Swarm/Portainer deployment

- Create single Dockerfile that builds frontend and backend together
- Add nginx.conf for combined container (proxies to localhost)
- Update docker-compose.prod.yml for Swarm compatibility:
  - Use pre-built image instead of build directive
  - Replace restart with deploy.restart_policy
  - Single 'app' service instead of separate backend/frontend

docker-compose.prod.yml

@@ -7,20 +7,15 @@ services:
     command: redis-server --appendonly yes
     volumes:
       - /mnt/DockerMount/minio-webui/redis:/data
-    restart: unless-stopped
     networks:
       - minio-webui-network
-    healthcheck:
-      test: ["CMD", "redis-cli", "ping"]
-      interval: 30s
-      timeout: 10s
-      retries: 3
+    deploy:
+      restart_policy:
+        condition: unless-stopped
 
-  # Backend API
-  backend:
-    build:
-      context: ./backend
-      dockerfile: ../docker/Dockerfile.backend
+  # Combined app (backend + frontend)
+  app:
+    image: theluap/minio-webui:latest
     environment:
       - NODE_ENV=production
       - PORT=3000
@@ -53,25 +48,9 @@ services:
       - /mnt/DockerMount/minio-webui/mc-config:/home/nodejs/.mc
     depends_on:
       - redis
-    restart: unless-stopped
-    networks:
-      - minio-webui-network
-    healthcheck:
-      test: ["CMD", "wget", "--quiet", "--tries=1", "--spider", "http://localhost:3000/health"]
-      interval: 30s
-      timeout: 10s
-      retries: 3
-      start_period: 40s
-
-  # Frontend (nginx + React)
-  frontend:
-    build:
-      context: ./frontend
-      dockerfile: ../docker/Dockerfile.frontend
-    depends_on:
-      - backend
-    restart: unless-stopped
     deploy:
+      restart_policy:
+        condition: unless-stopped
       labels:
         - "traefik.enable=true"
         - "traefik.http.routers.minio-webui.rule=Host(`minio-webui.local.nothaft.cloud`)"