Update Docker configuration for better backend service discovery

Dockerfile

@@ -7,6 +7,6 @@ RUN npm run build
 
 FROM nginx:alpine
 COPY --from=build /app/dist /usr/share/nginx/html
-COPY nginx.conf /etc/nginx/nginx.conf
+COPY nginx.conf /etc/nginx/templates/nginx.conf.template
 EXPOSE 80
-CMD ["nginx", "-g", "daemon off;"]
+CMD ["/docker-entrypoint.sh", "nginx", "-g", "daemon off;"]

nginx.conf

@@ -37,7 +37,7 @@ http {
 
         # Proxy API requests to the backend server
         location /api/ {
-            proxy_pass http://backend:3001/;
+            proxy_pass http://${BACKEND_HOST:-backend}:${BACKEND_PORT:-3001}/;
             proxy_http_version 1.1;
             proxy_set_header Upgrade $http_upgrade;
             proxy_set_header Connection 'upgrade';