chore: add Dockerfile and k8s deployment manifests

Dockerfile

@@ -0,0 +1,14 @@
+FROM node:22-alpine AS builder
+WORKDIR /app
+COPY package*.json ./
+RUN npm ci
+COPY . .
+RUN npm run build
+
+FROM node:22-alpine
+WORKDIR /app
+COPY --from=builder /app/build ./build
+COPY --from=builder /app/package*.json ./
+RUN npm ci --omit=dev
+EXPOSE 3000
+CMD ["node", "build/index.js"]