Optimize Dockerfile for security and efficiency

Dockerfile

@@ -1,9 +1,22 @@
-FROM node:19-alpine
-ENV PORT 8080
-
+# Stage 1: Build Stage
+FROM node:20-alpine AS build
 WORKDIR /usr/src/app
-
 RUN apk add --no-cache git
+COPY package*.json ./
+RUN npm install
 COPY . .
+
+# Stage 2: Production Stage
+FROM node:20-alpine
+ENV PORT 8080
+WORKDIR /usr/src/app
+COPY --from=build /usr/src/app .
+
+# Create a user for improved security
+RUN addgroup -S usergroup \
+    && adduser -S -D -h /usr/src/app appuser usergroup \
+    && chown -R appuser:usergroup /usr/src/app
+USER appuser
+
 EXPOSE 8080
 CMD ["npm", "start", "--no-update-notifier"]