Update to production Let's Encrypt certificates

frontend/Dockerfile

@@ -31,6 +31,9 @@ RUN npm run build
 # Stage 4: Production stage with nginx
 FROM nginx:alpine AS production
 
+# Add curl for healthchecks
+RUN apk add --no-cache curl
+
 # Create non-root user compatible with nginx
 RUN addgroup -g 1001 -S nodejs && \
     adduser -S nodejs -u 1001 -G nginx