fix: use full tag includes domain name and namespace in frontend

frontend/Dockerfile

@@ -4,7 +4,7 @@
 # =====================================================================
 
 # ---------- 构建阶段 ----------
-FROM node:24-alpine AS build
+FROM docker.io/library/node:24-alpine AS build
 WORKDIR /app
 
 # 使用与本地一致的 pnpm 主版本，锁定依赖保证可复现
@@ -18,7 +18,7 @@ COPY . .
 RUN pnpm build
 
 # ---------- 运行阶段 ----------
-FROM nginx:1.27-alpine
+FROM docker.io/library/nginx:1.27-alpine
 
 COPY nginx.conf /etc/nginx/conf.d/default.conf
 COPY --from=build /app/dist /usr/share/nginx/html