Add Dockerfile and docker-compose.yml

Dockerfile

@@ -0,0 +1,18 @@
+# Dockerfile for the Node.js checkpoint service
+FROM node:18-alpine
+
+# Set working directory
+WORKDIR /app
+
+# Copy package files and install dependencies
+COPY package.json package-lock.json ./
+RUN npm ci --only=production
+
+# Copy application source
+COPY . .
+
+# Expose the application port
+EXPOSE 3000
+
+# Run the application
+CMD ["npm", "start"]