chore: Remove nginx - use direct Caddy routing

- Remove nginx service from docker-compose
- Services bind to localhost:3000/3001 only
- Add Caddy configuration guide
- Update README with simplified structure
- External reverse proxy handles SSL/routing

docker-compose.yml

@@ -60,7 +60,7 @@ services:
       - OVERSEER_API_KEY=${OVERSEER_API_KEY}
       - ENCRYPTION_KEY=${ENCRYPTION_KEY}
     ports:
-      - "3001:3001"
+      - "127.0.0.1:3001:3001"  # Localhost only, Caddy proxies to this
     depends_on:
       postgres:
         condition: service_healthy
@@ -75,38 +75,23 @@ services:
       context: .
       dockerfile: frontend/Dockerfile
       args:
-        - NEXT_PUBLIC_API_URL=http://localhost:3001
+        - NEXT_PUBLIC_API_URL=${API_URL:-http://localhost:3001}
         - NEXT_PUBLIC_SOLANA_NETWORK=devnet
         - NEXT_PUBLIC_SOLANA_RPC_URL=https://api.devnet.solana.com
     container_name: coop-frontend
     environment:
-      - NEXT_PUBLIC_API_URL=http://localhost:3001
+      - NODE_ENV=production
+      - NEXT_PUBLIC_API_URL=${API_URL:-http://localhost:3001}
       - NEXT_PUBLIC_SOLANA_NETWORK=devnet
       - NEXT_PUBLIC_SOLANA_RPC_URL=https://api.devnet.solana.com
     ports:
-      - "3000:3000"
+      - "127.0.0.1:3000:3000"  # Localhost only, Caddy proxies to this
     depends_on:
       - backend
     networks:
       - coop-network
     restart: unless-stopped
 
-  nginx:
-    image: nginx:alpine
-    container_name: coop-nginx
-    ports:
-      - "80:80"
-    volumes:
-      - ./docker/nginx/nginx.conf:/etc/nginx/nginx.conf:ro
-    depends_on:
-      frontend:
-        condition: service_started
-      backend:
-        condition: service_healthy
-    networks:
-      - coop-network
-    restart: unless-stopped
-
 volumes:
   postgres_data:
   redis_data: