feat: add multi-stage Dockerfile for Astro webapp production deployment

Dockerfile

@@ -0,0 +1,34 @@
+# Dockerfile for Astro webapp
+# Use official Node.js image as the base
+FROM node:20-alpine as build
+
+# Set working directory
+WORKDIR /app
+
+# Copy package files and install dependencies
+COPY package.json package-lock.json ./
+RUN npm ci
+
+# Copy the rest of the application code
+COPY . .
+
+# Build the Astro project
+RUN npm run build
+
+# Production image
+FROM node:20-alpine as prod
+WORKDIR /app
+
+# Install only production dependencies
+COPY package.json package-lock.json ./
+RUN npm ci --omit=dev
+
+# Copy built files from build stage
+COPY --from=build /app/dist ./dist
+COPY public ./public
+
+# Expose Astro's default port
+EXPOSE 4321
+
+# Start the Astro preview server
+CMD ["npx", "astro", "preview"]