feat: 外观支持自定义 CSS/JS，并升级发帖工作台与积分存量看板

后台可注入全站 CSS/JS（SSR 生效，CSS 可热换）；发帖/编辑改为锁一屏工作室；经济看板增加存量健康度；主题令牌与弹层误关一并收紧。

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

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

@@ -1,7 +1,5 @@
 import { cookies } from "next/headers";
 import { notFound, redirect } from "next/navigation";
-import Link from "next/link";
-import { ChevronRight } from "lucide-react";
 import { authCookieHeader } from "@/lib/cookies";
 import { getMeCached } from "@/lib/serverData";
 import { fetchPostDetail } from "@/lib/api";
@@ -35,25 +33,7 @@ export default async function EditPostPage({ params }: PageProps) {
   }
 
   return (
-    <div
-      data-compose-viewport
-      className="j13-compose-page w-full"
-    >
-      <nav className="meta -mt-4 sm:-mt-6 mb-1.5 flex items-center gap-1 flex-wrap text-[12.5px] leading-none shrink-0">
-        <Link href="/" className="hover:text-[var(--accent)] transition-colors">
-          首页
-        </Link>
-        <ChevronRight size={13} />
-        <Link
-          href={`/post/${post.id}`}
-          className="hover:text-[var(--accent)] transition-colors truncate max-w-[12rem]"
-        >
-          帖子详情
-        </Link>
-        <ChevronRight size={13} />
-        <span style={{ color: "var(--ink-2)" }}>编辑</span>
-      </nav>
-
+    <div className="j13-compose-page w-full">
       <EditPostClient
         postId={post.id}
         initialTitle={post.title}