add docker files

backend/Dockerfile

@@ -0,0 +1,20 @@
+# Use the official Node.js 23.10 image
+FROM node:23.10
+
+# Set working directory inside the container
+WORKDIR /app
+
+# Copy only package.json and lock file first for caching
+COPY package*.json ./
+
+# Install dependencies
+RUN npm install
+
+# Copy the rest of the app (after installing dependencies for cache efficiency)
+COPY . .
+
+# Expose the port your server listens on (adjust if needed)
+EXPOSE 8005
+
+# Start the app
+CMD ["node", "server.js"]