feat: 顶栏显示当前页名,去掉独立标题行;Logo回首页/页名回顶部

- 新增 PageTitleContext:页面上报标题,顶栏 brand 位显示当前页名(全部资料/
  热门资料/最新/官方/分类名/搜索/我的收藏),未上报则回退品牌名
- AssetStreamPage、Favorites 上报标题;移除资料流内单独的标题行,省出空间
- 顶栏拆分点击:Logo→首页(首页则回顶部);页名文字→回到当前页顶部

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/layouts/PublicLayout.tsx

@@ -4,6 +4,7 @@ import { useEffect, useRef, useState } from "react";
 import { Link, useLocation, useNavigate, useOutlet } from "react-router-dom";
 import { pageTransition } from "../motion";
 import { ArkLogoMark } from "../components/ArkLogoMark";
+import { usePageTitle } from "../components/PageTitleContext";
 import { BackToTop } from "../components/BackToTop";
 import { DocumentMeta } from "../components/DocumentMeta";
 import { SearchPanel } from "../components/SearchPanel";
@@ -289,6 +290,8 @@ export function PublicLayout() {
     navIsActive(pathname, search, hash, which);
   const isHome = pathname === "/";
   const footerInContentFlow = pathname === "/browse";
+  // Current page name shown in the header brand slot (falls back to the brand).
+  const pageTitle = usePageTitle();
   const popularHref = "/browse?sort=popular";
 
   const goSearch = () => {
@@ -365,20 +368,29 @@ export function PublicLayout() {
       <DocumentMeta />
       <header className="sticky top-0 z-40 bg-[#08070c] backdrop-blur-md md:border-b md:border-ark-line md:bg-ark-nav/98">
         <div className="flex h-[64px] items-center justify-between bg-[#08070c] px-4 py-3 md:hidden">
-          <Link
-            to="/"
-            className="flex h-8 shrink-0 items-center gap-2 rounded-sm text-[20px] font-black leading-5 tracking-tight text-ark-gold outline-none focus-visible:ring-2 focus-visible:ring-ark-gold/80 focus-visible:ring-offset-2 focus-visible:ring-offset-[#08070c]"
-            aria-label={t("brand")}
-            onClick={(e) => {
-              if (isHome) {
-                e.preventDefault();
-                window.scrollTo({ top: 0, behavior: "smooth" });
-              }
-            }}
-          >
-            <ArkLogoMark className="h-8 w-8 shrink-0" />
-            <span className="truncate text-ark-gold">{t("brand")}</span>
-          </Link>
+          <div className="flex h-8 min-w-0 shrink items-center gap-2 text-[20px] font-black leading-5 tracking-tight text-ark-gold">
+            {/* Logo → home; page-name text → scroll to top of the current page. */}
+            <Link
+              to="/"
+              aria-label={t("brand")}
+              onClick={(e) => {
+                if (isHome) {
+                  e.preventDefault();
+                  window.scrollTo({ top: 0, behavior: "smooth" });
+                }
+              }}
+              className="shrink-0 rounded-sm outline-none focus-visible:ring-2 focus-visible:ring-ark-gold/80 focus-visible:ring-offset-2 focus-visible:ring-offset-[#08070c]"
+            >
+              <ArkLogoMark className="h-8 w-8 shrink-0" />
+            </Link>
+            <button
+              type="button"
+              onClick={() => window.scrollTo({ top: 0, behavior: "smooth" })}
+              className="truncate rounded-sm text-left text-ark-gold outline-none focus-visible:ring-2 focus-visible:ring-ark-gold/80 focus-visible:ring-offset-2 focus-visible:ring-offset-[#08070c]"
+            >
+              {pageTitle || t("brand")}
+            </button>
+          </div>
 
           <div className="flex h-[40px] w-[136px] shrink-0 items-center gap-[8px]">
             <button
@@ -441,21 +453,29 @@ export function PublicLayout() {
         <div className="mx-auto hidden max-w-[1280px] px-4 py-[15px] min-[440px]:px-5 sm:px-6 md:block md:px-9 xl:px-0">
           {/* Single row (md+): logo | scrollable nav (左對齊，可橫向滑動) | 搜尋 + 語言 */}
           <div className="flex h-10 items-center gap-2 min-[1200px]:gap-0 lg:gap-4">
-            <Link
-              to="/"
-              className="flex min-w-0 shrink-0 items-center gap-2.5 rounded-sm text-xl font-bold tracking-wide text-ark-gold outline-none focus-visible:ring-2 focus-visible:ring-ark-gold/80 focus-visible:ring-offset-2 focus-visible:ring-offset-ark-bg"
-              onClick={(e) => {
-                if (isHome) {
-                  e.preventDefault();
-                  window.scrollTo({ top: 0, behavior: "smooth" });
-                }
-              }}
-            >
-              <ArkLogoMark className="h-10 w-10 shrink-0" />
-              <span className="max-w-[8rem] truncate text-ark-gold sm:inline">
-                {t("brand")}
-              </span>
-            </Link>
+            <div className="flex min-w-0 shrink items-center gap-2.5 text-xl font-bold tracking-wide text-ark-gold">
+              {/* Logo → home; page-name text → scroll to top of the current page. */}
+              <Link
+                to="/"
+                aria-label={t("brand")}
+                onClick={(e) => {
+                  if (isHome) {
+                    e.preventDefault();
+                    window.scrollTo({ top: 0, behavior: "smooth" });
+                  }
+                }}
+                className="shrink-0 rounded-sm outline-none focus-visible:ring-2 focus-visible:ring-ark-gold/80 focus-visible:ring-offset-2 focus-visible:ring-offset-ark-bg"
+              >
+                <ArkLogoMark className="h-10 w-10 shrink-0" />
+              </Link>
+              <button
+                type="button"
+                onClick={() => window.scrollTo({ top: 0, behavior: "smooth" })}
+                className="max-w-[10rem] truncate rounded-sm text-left text-ark-gold outline-none focus-visible:ring-2 focus-visible:ring-ark-gold/80 focus-visible:ring-offset-2 focus-visible:ring-offset-ark-bg sm:inline"
+              >
+                {pageTitle || t("brand")}
+              </button>
+            </div>
 
             <nav
               className="header-nav-scroll hidden min-w-0 flex-1 items-center justify-center gap-4 overflow-x-auto overflow-y-hidden py-1 min-[1200px]:flex lg:gap-5"