add docker support

Dockerfile

@@ -0,0 +1,20 @@
+# Use Node.js official image
+FROM node:lts-alpine
+
+# Set working directory
+WORKDIR /app
+
+# Copy package files
+COPY package*.json ./
+
+# Install dependencies
+RUN npm ci --only=production
+
+# Copy application files
+COPY . .
+
+# Expose port
+EXPOSE 3000
+
+# Start the application
+CMD ["npm", "start"]