Add Docker configuration for deployment and fix Supabase types for contacts table

Dockerfile.backend

@@ -0,0 +1,20 @@
+# Use Node.js alpine image
+FROM node:18-alpine
+
+# Set working directory
+WORKDIR /app
+
+# Copy package files
+COPY package*.json ./
+
+# Install dependencies
+RUN npm ci --only=production
+
+# Copy all files
+COPY . .
+
+# Expose port 3001
+EXPOSE 3001
+
+# Start the application
+CMD ["node", "server.js"]