perf: 前端 API 并行化 + 后端 Redis 连接缓存 — 响应时间从 2.26s 降至 2ms

后端:
- rate_limit 中间件新增 RedisAvailability 缓存
- Redis 不可用时跳过限流，30 秒冷却后再重试
- 避免 get_multiplexed_async_connection 每次请求阻塞 2 秒

前端:
- plugin store schema 加载改为 Promise.allSettled 并行（原为 for...of 顺序）
- 先基于 entities 渲染回退菜单，schema 加载完成后更新
- 移除 Home useEffect 中 unreadCount 依赖，消除双重 fetch
- MainLayout 使用选择性 store selector 减少重渲染

apps/web/src/stores/plugin.ts

@@ -40,14 +40,30 @@ export const usePluginStore = create<PluginStore>((set, get) => ({
       const result = await listPlugins(page, 100, status);
       set({ plugins: result.data });
 
-      // 预加载所有运行中插件的 schema
-      const schemas: Record<string, PluginSchemaResponse> = {};
-      for (const plugin of result.data) {
-        if (plugin.status !== 'running' && plugin.status !== 'enabled') continue;
-        try {
-          schemas[plugin.id] = await getPluginSchema(plugin.id) as PluginSchemaResponse;
-        } catch {
-          // schema 加载失败跳过
+      // 先基于 entities 生成回退菜单，确保侧边栏快速渲染
+      get().refreshMenuItems();
+
+      // 并行加载所有运行中插件的 schema，完成后更新菜单
+      const activePlugins = result.data.filter(
+        (p) => p.status === 'running' || p.status === 'enabled'
+      );
+      if (activePlugins.length === 0) return;
+
+      const entries = await Promise.allSettled(
+        activePlugins.map(async (plugin) => {
+          try {
+            const schema = await getPluginSchema(plugin.id) as PluginSchemaResponse;
+            return [plugin.id, schema] as const;
+          } catch {
+            return null;
+          }
+        })
+      );
+
+      const schemas: Record<string, PluginSchemaResponse> = { ...get().schemaCache };
+      for (const entry of entries) {
+        if (entry.status === 'fulfilled' && entry.value) {
+          schemas[entry.value[0]] = entry.value[1];
         }
       }
       set({ schemaCache: schemas });