deploy: add notification service Dockerfile

Dockerfile.notification-service

@@ -0,0 +1,22 @@
+FROM node:20-alpine AS builder
+
+WORKDIR /app
+
+COPY package*.json ./
+RUN npm ci
+
+COPY . .
+RUN npm run build:notifications
+
+FROM node:20-alpine AS runner
+
+WORKDIR /app
+
+ENV NODE_ENV=production
+
+COPY package*.json ./
+RUN npm ci --omit=dev && npm cache clean --force
+
+COPY --from=builder /app/dist/apps/notification-service ./dist/apps/notification-service
+
+CMD ["node", "dist/apps/notification-service/main.js"]