T01: update backend Dockerfile

backend/Dockerfile

@@ -1,13 +1,23 @@
+# Use Node.js 22 LTS as base image
 FROM node:22-alpine
-RUN apk add --no-cache curl
 
+# Set working directory
 WORKDIR /app
 
+# Copy package files
 COPY package*.json ./
-RUN npm ci --only=production
 
+# Install dependencies
+RUN npm ci
+
+# Copy source code
 COPY . .
 
-EXPOSE 5000
+# Build the application
+RUN npm run build
 
-CMD ["node", "server.js"]
+# Expose port 3001
+EXPOSE 3001
+
+# Run the application
+CMD ["npm", "start"]