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/app/post/[id]/page.tsx

@@ -581,21 +581,17 @@ export default async function PostDetailPage({ params, searchParams }: PageProps
         </aside>
 
         {/* 中栏：正文主体 */}
-        <div className="min-w-0 relative">
-          <SiteDocBreadcrumb
-            items={[
-              { href: "/", label: "首页" },
-              { href: `/?board=${post.board.id}`, label: post.board.name },
-            ]}
-          />
+        <div className="min-w-0">
           <article className="w-full">
             <div className="panel p-6 sm:p-8">
+              <SiteDocBreadcrumb
+                className="is-ruled"
+                items={[
+                  { href: "/", label: "首页" },
+                  { href: `/?board=${post.board.id}`, label: post.board.name },
+                ]}
+              />
               <header className="mb-7">
-                <div className="flex items-center gap-2 mb-4 flex-wrap">
-                  <Link href={`/?board=${post.board.id}`} className="chip">
-                    {post.board.name}
-                  </Link>
-                </div>
                 <div className="flex items-start gap-2 flex-wrap mb-6">
                   {/* 仅置顶/推荐在标题左侧 */}
                   {post.pinned > 0 && <span className="badge-pin shrink-0 mt-2 sm:mt-3">置顶</span>}