all these changes

frontend/Dockerfile

@@ -1,26 +1,23 @@
-###
-### Frontend development image (hot reload)
-### Runs CRA dev server for fast iteration behind Traefik
-###
-
-FROM node:18-alpine
+FROM node:20-alpine AS build
 
 WORKDIR /app
 
-# Install dependencies
 COPY package*.json ./
-RUN npm install --silent
+RUN npm ci --silent
 
-# Copy source code
 COPY . .
 
-# Dev-friendly env for Docker volumes
-ENV CHOKIDAR_USEPOLLING=true \
-    WATCHPACK_POLLING=true \
-    WDS_SOCKET_PORT=0 \
-    DANGEROUSLY_DISABLE_HOST_CHECK=true
+ARG VITE_API_URL=/api
+ENV VITE_API_URL=${VITE_API_URL}
 
-EXPOSE 3000
+RUN npm run build
 
-# Start CRA dev server (HMR)
-CMD ["npm", "start"]
+FROM nginx:1.27-alpine
+
+COPY nginx.conf /etc/nginx/conf.d/default.conf
+COPY --from=build /app/dist /usr/share/nginx/html
+
+EXPOSE 80
+
+HEALTHCHECK --interval=30s --timeout=5s --start-period=15s --retries=3 \
+  CMD wget -q -O /dev/null http://127.0.0.1/ || exit 1