feat: proxy embed assets to in-cluster project57 [deploy]

Dockerfile

@@ -1,5 +1,10 @@
-# CI 中先 pnpm build 产出 dist/，镜像只负责托管静态文件
+# CI 中先 pnpm build 产出 dist/；运行时由 nginx 托管，并把 /embed /images /api/contact 反代到 A 站
 FROM nginx:1.27-alpine
-COPY nginx.conf /etc/nginx/conf.d/default.conf
+
+# 集群内 A 站地址，可被 K8s env 覆盖
+ENV A_UPSTREAM=http://project57-deploy.ns-project57.svc.cluster.local:3000
+
+COPY nginx.conf /etc/nginx/templates/default.conf.template
 COPY dist /usr/share/nginx/html
+
 EXPOSE 3000