fix: update dockerfile, gh workflow

Dockerfile

@@ -1,8 +1,14 @@
-FROM node:22-alpine
+# Build stage
+FROM node:20-alpine as build
 ARG APP_DIR=app
 RUN mkdir -p ${APP_DIR}
 WORKDIR ${APP_DIR}
+
 COPY package*.json ./
-RUN npm install
-COPY ./build ./
-CMD ["npm", "start"]
+RUN npm ci && npm cache clean --force
+CMD ["npm", "run", "build"]
+
+# Run stage
+FROM node:20-alpine
+COPY --from=build ./build ./
+CMD ["node", "index.js"]