Clean up drift: restore Dockerfile name, remove cache bust artifacts

products/02-iac-drift-detection/saas/Dockerfile

@@ -0,0 +1,15 @@
+FROM node:22-slim AS builder
+WORKDIR /app
+ARG CACHE_BUST=1
+COPY package.json package-lock.json* ./
+RUN npm ci --include=dev
+COPY . .
+RUN npm run build
+
+FROM node:22-slim
+WORKDIR /app
+COPY --from=builder /app/dist ./dist
+COPY --from=builder /app/node_modules ./node_modules
+COPY --from=builder /app/package.json ./
+EXPOSE 3000
+CMD ["node", "dist/index.js"]