chore: add lightweight Dockerfile for deployment

Dockerfile

@@ -0,0 +1,21 @@
+FROM node:20-alpine
+
+WORKDIR /app
+
+# Copy package files
+COPY package*.json ./
+
+# Install dependencies (including devDependencies for building and running drizzle)
+RUN npm ci
+
+# Copy the rest of the application files
+COPY . .
+
+# Build the frontend and backend api
+RUN npm run build
+
+# Expose port
+EXPOSE 3000
+
+# Start command
+CMD ["npm", "run", "start"]