feat: 首页 Go SSR 与 React hydrate 同构，消壳层与帖行闪动

补齐侧栏/右栏图标与徽章、鉴权种子、StaticFeedList，并修正嵌套 a 与标题徽章对齐。

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

frontend/src/utils/softRefresh.ts

@@ -1,13 +1,21 @@
 import { prefetchLayoutShell, prefetchRoute } from './prefetchRoute';
+import { doneTransition, startTransition } from './spaTransition';
 
 /** 软刷新齐套后的单一提交：各组件同一拍从 cache/快照同步 UI，禁止分批闪烁 */
 export const PAGE_SOFT_REFRESH_COMMIT_EVENT = 'page-soft-refresh-commit';
 
+export type SoftRefreshOpts = {
+  /** 是否显示顶栏进度条（Logo 刷新开；下拉关） */
+  progress?: boolean;
+};
+
 /**
- * 静默刷新当前页：不改画面、无进度条，预热齐套后派发一次 commit。
+ * 软刷新当前页：预热齐套后派发一次 commit。
+ * `progress: true` 时走顶栏进度条。
  */
-export async function softRefreshCurrentPage(to?: string): Promise<void> {
+export async function softRefreshCurrentPage(to?: string, opts?: SoftRefreshOpts): Promise<void> {
   const path = to ?? `${window.location.pathname}${window.location.search}`;
+  const id = opts?.progress ? startTransition() : undefined;
   try {
     await Promise.all([
       prefetchRoute(path, { force: true }),
@@ -17,4 +25,5 @@ export async function softRefreshCurrentPage(to?: string): Promise<void> {
     // 仍派发 commit，让界面有机会用已有缓存自愈
   }
   window.dispatchEvent(new Event(PAGE_SOFT_REFRESH_COMMIT_EVENT));
+  if (id != null) doneTransition(id);
 }