refactor: update frontend Dockerfile

frontend/Dockerfile

@@ -1,16 +1,11 @@
-FROM node:24.18.1-slim AS frontend-build
+FROM node-pnpm-base:24.18.1 AS frontend-build
 WORKDIR /app
-RUN corepack enable && corepack prepare pnpm@10.15.1 --activate
 COPY frontend/package.json frontend/pnpm-lock.yaml ./
 RUN pnpm install --frozen-lockfile
 COPY frontend/ ./
 RUN pnpm typecheck && pnpm build
 
-FROM nginx:alpine
-ENV TZ=Asia/Shanghai
-RUN apk add --no-cache tzdata \
-    && ln -snf /usr/share/zoneinfo/$TZ /etc/localtime \
-    && echo $TZ > /etc/timezone
+FROM nginx-base:alpine
 COPY ./default.conf /etc/nginx/conf.d/default.conf.template
 COPY ./scripts/nginx-entrypoint.sh /usr/local/bin/model-platform-entrypoint.sh
 RUN sed -i 's/\r$//' /usr/local/bin/model-platform-entrypoint.sh \