feat: 交付官方 Docker 运行时，外观改背景图并下线自定义 CSS/JS

站点/后台分轨背景与用户列表排序一并落地；生产 CORS 改走 SITE_URL，健康检查带版本号。

Co-authored-by: Cursor <cursoragent@cursor.com>

frontend/components/PostRow.tsx

@@ -45,7 +45,7 @@ export default async function PostRow({
 
   return (
     <div
-      className={`group relative flex items-center px-4 sm:px-5 border-t cursor-pointer transition-colors hover:bg-[var(--panel-2)] focus-within:bg-[var(--panel-2)] j13-fade-up ${
+      className={`group relative flex items-center px-4 sm:px-5 border-t cursor-pointer transition-colors hover:bg-[var(--item-hover-bg)] focus-within:bg-[var(--item-hover-bg)] j13-fade-up ${
         compact ? "gap-2.5 sm:gap-3" : "gap-3.5 sm:gap-4"
       }`}
       style={{