feat: SSR 请求级作用域（AsyncLocalStorage）+ homeStore 工厂化 + layoutCache 作用域适配

frontend/src/utils/layoutCache.ts

@@ -1,4 +1,5 @@
 import type { Board, ForumStats, RecentComment, RecentUser, TagCount } from '../api/types';
+import { getScope } from '../ssr/scope';
 
 const BOARDS_KEY = 'j13-cache-boards';
 const STATS_KEY = 'j13-cache-stats';
@@ -6,7 +7,12 @@ const RECENT_COMMENTS_KEY = 'j13-cache-recent-comments';
 const RECENT_USERS_KEY = 'j13-cache-recent-users';
 const TAGS_KEY = 'j13-cache-tags';
 
+/** SSR 请求期写入 RequestScope.kv；客户端写 sessionStorage */
 function readJson<T>(key: string): T | null {
+  const scope = getScope();
+  if (scope) {
+    return (scope.kv.get(key) as T | undefined) ?? null;
+  }
   try {
     const raw = sessionStorage.getItem(key);
     return raw ? (JSON.parse(raw) as T) : null;
@@ -16,6 +22,11 @@ function readJson<T>(key: string): T | null {
 }
 
 function writeJson(key: string, value: unknown) {
+  const scope = getScope();
+  if (scope) {
+    scope.kv.set(key, value);
+    return;
+  }
   try {
     sessionStorage.setItem(key, JSON.stringify(value));
   } catch {
@@ -53,6 +64,12 @@ export function getCachedTags(): TagCount[] {
 
 /** 右栏是否已有可展示的 session 缓存（含空列表） */
 export function hasCachedAside(): boolean {
+  const scope = getScope();
+  if (scope) {
+    return scope.kv.has(RECENT_COMMENTS_KEY)
+      || scope.kv.has(RECENT_USERS_KEY)
+      || scope.kv.has(TAGS_KEY);
+  }
   try {
     return sessionStorage.getItem(RECENT_COMMENTS_KEY) != null
       || sessionStorage.getItem(RECENT_USERS_KEY) != null