Switch to standard nginx for port 80 compatibility

Dockerfile

@@ -2,12 +2,13 @@
 FROM node:22-alpine AS build
 WORKDIR /app
 COPY package*.json ./
-RUN npm install
+RUN npm install --frozen-lockfile
 COPY . .
 RUN npm run build
 
 # Production stage
-FROM nginxinc/nginx-unprivileged:alpine
+FROM nginx:alpine
 COPY --from=build /app/dist /usr/share/nginx/html
-EXPOSE 8080
+# Nginx default listens on 80
+EXPOSE 80
 CMD ["nginx", "-g", "daemon off;"]