feat(web): 页头滚动信息、移除返回按钮、面包屑左侧可点、侧栏加首页

- 页头中间信息改为无缝滚动 ticker（3 份拼接，24s 线性，尊重 reduced-motion）
- 去掉分区 / 条目 / 文章三处「返回」「返回首页」按钮
- 面包屑移到左侧，中间项可点击并通过 onNavigate 走 SPA 路由
- 侧栏新增「首页」，首页时高亮，点击回首页

stash-web/src/components/header/SiteHeader.tsx

@@ -1,8 +1,7 @@
-import { Icon, IconButton, Space } from '@stash/ui'
-import { HeaderInfoItem } from './HeaderInfoItem'
+import { Icon, IconButton, Tag } from '@stash/ui'
 
 /**
- * 顶部栏：左品牌、中间运行信息、右侧操作图标。
+ * 顶部栏：左品牌、中间滚动信息、右侧操作图标。
  * 外层 <header> 由 Layout 提供，这里只渲染栏内的内容。
  */
 type SiteHeaderProps = {
@@ -13,6 +12,40 @@ type SiteHeaderProps = {
   onFocusSearch: () => void
 }
 
+type InfoGroupProps = Omit<SiteHeaderProps, 'onFocusSearch'> & {
+  'aria-hidden'?: boolean
+}
+
+/** 运行信息：同一份内容渲染两遍，轨道平移 50% 形成无缝滚动 */
+function InfoGroup({
+  projectCount,
+  sampleProject,
+  live,
+  'aria-hidden': ariaHidden,
+}: InfoGroupProps) {
+  return (
+    <span className="header-ticker-group" aria-hidden={ariaHidden}>
+      <span className="header-ticker-item">共 {projectCount} 个本地应用</span>
+
+      {sampleProject !== undefined && (
+        <span className="header-ticker-item">
+          <Tag tone="primary" shape="rounded">
+            本地
+          </Tag>
+          {sampleProject}
+        </span>
+      )}
+
+      <span className="header-ticker-item">
+        <Tag tone={live ? 'success' : 'neutral'} shape="rounded">
+          状态
+        </Tag>
+        {live ? '实时同步已连接' : '等待服务连接'}
+      </span>
+    </span>
+  )
+}
+
 export function SiteHeader({ projectCount, sampleProject, live, onFocusSearch }: SiteHeaderProps) {
   return (
     <div className="site-header-inner">
@@ -23,19 +56,26 @@ export function SiteHeader({ projectCount, sampleProject, live, onFocusSearch }:
         <span className="site-brand-name">STASH</span>
       </a>
 
-      <Space gap="lg" className="header-info">
-        <HeaderInfoItem>共 {projectCount} 个本地应用</HeaderInfoItem>
+      <div className="header-ticker" role="status" aria-label="运行状态">
+        <div className="header-ticker-track">
+          <InfoGroup projectCount={projectCount} sampleProject={sampleProject} live={live} />
+          <InfoGroup
+            projectCount={projectCount}
+            sampleProject={sampleProject}
+            live={live}
+            // 后两份只用于视觉无缝，读屏忽略
+            aria-hidden
+          />
+          <InfoGroup
+            projectCount={projectCount}
+            sampleProject={sampleProject}
+            live={live}
+            aria-hidden
+          />
+        </div>
+      </div>
 
-        {sampleProject !== undefined && (
-          <HeaderInfoItem tag="本地">{sampleProject}</HeaderInfoItem>
-        )}
-
-        <HeaderInfoItem tag="状态" tone={live ? 'green' : 'blue'}>
-          {live ? '实时同步已连接' : '等待服务连接'}
-        </HeaderInfoItem>
-      </Space>
-
-      <Space gap="sm" className="header-actions">
+      <div className="header-actions">
         <IconButton
           label="聚焦搜索框（Ctrl+K）"
           icon={<Icon name="search_3_line" />}
@@ -43,7 +83,7 @@ export function SiteHeader({ projectCount, sampleProject, live, onFocusSearch }:
         />
         {/* TODO(auth): 后端登录接口就绪后接上，目前仅作入口占位 */}
         <IconButton label="登录" icon={<Icon name="user_3_line" />} />
-      </Space>
+      </div>
     </div>
   )
 }