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/components/messageStream/MessageStream.tsx

@@ -6,17 +6,15 @@ import type { PostScope } from "../../types/post";
 import { Reveal } from "../../motion";
 import { Skeleton } from "../Skeleton";
 import { FilterChips } from "./FilterChips";
-import { SectionHeader } from "../SectionHeader";
 import { MessageBubble } from "./MessageBubble";
 import { useGroupedByDay } from "./hooks/useGroupedByDay";
 import { usePostStream } from "./hooks/usePostStream";
 
 export type MessageStreamProps = {
   scope: PostScope;
-  title?: string;
 };
 
-export function MessageStream({ scope, title }: MessageStreamProps) {
+export function MessageStream({ scope }: MessageStreamProps) {
   const { t, lang } = useI18n();
   const [sp, setSp] = useSearchParams();
   const { hash } = useLocation();
@@ -116,14 +114,9 @@ export function MessageStream({ scope, title }: MessageStreamProps) {
 
   return (
     <div className="mx-auto max-w-full md:max-w-[820px] lg:max-w-[1080px] xl:max-w-[1180px]">
-      {/* Title + filters stay pinned below the global header so users always
-          see which page they're on and can switch filters while scrolling. */}
+      {/* Filters stay pinned below the global header (which shows the page
+          name) so users can switch filters while scrolling. */}
       <div className="sticky top-[64px] z-30 bg-ark-bg md:top-[70px]">
-        {title ? (
-          <div className="px-4 pb-1 pt-2 md:px-0">
-            <SectionHeader title={title} />
-          </div>
-        ) : null}
         <FilterChips type={type} onTypeChange={(v) => updateParam("type", v)} />
       </div>