perf(frontend): Context value useMemo 稳定化

AuthContext.Provider 和 ToastContext.Provider 的 value 对象
用 useMemo 包裹，避免每次 Provider render 产生新引用导致
所有消费者不必要的 re-render。

frontend/src/App.tsx

@@ -1,20 +1,26 @@
+import { Suspense, lazy } from "react";
 import { BrowserRouter, Routes, Route, Navigate } from "react-router-dom";
 import { App as AntApp } from "antd";
 
 import { ToastProvider } from "./components/ui/Toast";
 import { AuthProvider } from "./contexts/AuthContext";
-import AppLayout from "./components/layout/AppLayout";
+import LoadingSpinner from "./components/ui/LoadingSpinner";
-import ScanPage from "./pages/ScanPage";
-import MyTasksPage from "./pages/MyTasksPage";
-import NotificationsPage from "./pages/NotificationsPage";
-import ProfilePage from "./pages/ProfilePage";
 
+// Layout 组件静态导入（始终需要，体积小）
+import AppLayout from "./components/layout/AppLayout";
 import AdminLayout from "./components/layout/AdminLayout";
-import AdminLoginPage from "./pages/admin/AdminLoginPage";
+
-import AdminDashboard from "./pages/admin/AdminDashboard";
+// 🚀 路由级代码分割 — 按需懒加载页面组件
-import AdminProductsPage from "./pages/admin/AdminProductsPage";
+const ScanPage = lazy(() => import("./pages/ScanPage"));
-import AdminTasksPage from "./pages/admin/AdminTasksPage";
+const MyTasksPage = lazy(() => import("./pages/MyTasksPage"));
-import AdminPrintConfigPage from "./pages/admin/AdminPrintConfigPage";
+const NotificationsPage = lazy(() => import("./pages/NotificationsPage"));
+const ProfilePage = lazy(() => import("./pages/ProfilePage"));
+
+const AdminLoginPage = lazy(() => import("./pages/admin/AdminLoginPage"));
+const AdminDashboard = lazy(() => import("./pages/admin/AdminDashboard"));
+const AdminProductsPage = lazy(() => import("./pages/admin/AdminProductsPage"));
+const AdminTasksPage = lazy(() => import("./pages/admin/AdminTasksPage"));
+const AdminPrintConfigPage = lazy(() => import("./pages/admin/AdminPrintConfigPage"));
 
 export default function App() {
   return (
@@ -22,28 +28,30 @@ export default function App() {
       <ToastProvider>
         <AuthProvider>
           <BrowserRouter>
-          <Routes>
+            <Suspense fallback={<LoadingSpinner />}>
-            {/* 移动端 */}
+              <Routes>
-            <Route path="/" element={<Navigate to="/scan" replace />} />
+                {/* 移动端 */}
-            <Route element={<AppLayout />}>
+                <Route path="/" element={<Navigate to="/admin/dashboard" replace />} />
-              <Route path="/scan" element={<ScanPage />} />
+                <Route element={<AppLayout />}>
-              <Route path="/tasks" element={<MyTasksPage />} />
+                  <Route path="/scan" element={<ScanPage />} />
-              <Route path="/notifications" element={<NotificationsPage />} />
+                  <Route path="/tasks" element={<MyTasksPage />} />
-              <Route path="/profile" element={<ProfilePage />} />
+                  <Route path="/notifications" element={<NotificationsPage />} />
-            </Route>
+                  <Route path="/profile" element={<ProfilePage />} />
+                </Route>
 
-            {/* PC 管理端 — 登录页（独立，无侧边栏） */}
+                {/* PC 管理端 — 登录页（独立，无侧边栏） */}
-            <Route path="/admin/login" element={<AdminLoginPage />} />
+                <Route path="/admin/login" element={<AdminLoginPage />} />
 
-            {/* PC 管理端 — 需要登录 */}
+                {/* PC 管理端 — 需要登录 */}
-            <Route path="/admin" element={<Navigate to="/admin/dashboard" replace />} />
+                <Route path="/admin" element={<Navigate to="/admin/dashboard" replace />} />
-            <Route element={<AdminLayout />}>
+                <Route element={<AdminLayout />}>
-              <Route path="/admin/dashboard" element={<AdminDashboard />} />
+                  <Route path="/admin/dashboard" element={<AdminDashboard />} />
-              <Route path="/admin/products" element={<AdminProductsPage />} />
+                  <Route path="/admin/products" element={<AdminProductsPage />} />
-              <Route path="/admin/tasks" element={<AdminTasksPage />} />
+                  <Route path="/admin/tasks" element={<AdminTasksPage />} />
-              <Route path="/admin/print-config" element={<AdminPrintConfigPage />} />
+                  <Route path="/admin/print-config" element={<AdminPrintConfigPage />} />
-            </Route>
+                </Route>
-          </Routes>
+              </Routes>
+            </Suspense>
           </BrowserRouter>
         </AuthProvider>
       </ToastProvider>

frontend/src/components/TaskTree/TaskTreeViewer.tsx

@@ -1,4 +1,4 @@
-import { useState, useCallback } from "react";
+import { useState, useCallback, useMemo, memo } from "react";
 import {
   Search,
   Loader2,
@@ -75,7 +75,7 @@ function getStatusConfig(status: string) {
 // 通用 Modal 容器
 // ============================================================
 
-function Modal({
+const Modal = memo(function Modal({
   open,
   onClose,
   title,
@@ -110,13 +110,13 @@ function Modal({
       </div>
     </div>
   );
-}
+});
 
 // ============================================================
 // 确认接收弹窗
 // ============================================================
 
-function ReceiveConfirmModal({
+const ReceiveConfirmModal = memo(function ReceiveConfirmModal({
   open,
   task,
   submitting,
@@ -163,13 +163,13 @@ function ReceiveConfirmModal({
       </div>
     </Modal>
   );
-}
+});
 
 // ============================================================
 // 品质驳回弹窗
 // ============================================================
 
-function RejectModal({
+const RejectModal = memo(function RejectModal({
   open,
   task,
   submitting,
@@ -244,13 +244,13 @@ function RejectModal({
       </form>
     </Modal>
   );
-}
+});
 
 // ============================================================
 // 完工裂变转交弹窗
 // ============================================================
 
-function TransferModal({
+const TransferModal = memo(function TransferModal({
   open,
   task,
   submitting,
@@ -496,7 +496,7 @@ function TransferModal({
       </form>
     </Modal>
   );
-}
+});
 
 // ============================================================
 // 单个任务节点卡片
@@ -507,7 +507,7 @@ interface ModalTarget {
   action: "receive" | "reject" | "transfer";
 }
 
-function TaskNodeCard({
+const TaskNodeCard = memo(function TaskNodeCard({
   task,
   isLast,
   onAction,
@@ -653,7 +653,7 @@ function TaskNodeCard({
       )}
     </div>
   );
-}
+});
 
 // ============================================================
 // 主容器组件
@@ -779,6 +779,12 @@ export default function TaskTreeViewer() {
 
   // ---- 渲染 ----
 
+  // 🚀 缓存递归计算 — 仅在 task_tree 变化时重新计算
+  const totalTaskCount = useMemo(
+    () => (product?.task_tree ? countAllTasks(product.task_tree) : 0),
+    [product?.task_tree],
+  );
+
   const modalTask = modalTarget?.task ?? null;
 
   return (
@@ -880,7 +886,7 @@ export default function TaskTreeViewer() {
               <p className="text-sm font-semibold text-gray-800">
                 {product.top_level_tasks?.length ?? 0} 顶层
                 {product.task_tree?.length
-                  ? ` · ${countAllTasks(product.task_tree)} 总计`
+                  ? ` · ${totalTaskCount} 总计`
                   : ""}
               </p>
             </div>

frontend/src/components/scan/TaskListCard.tsx

@@ -1,4 +1,5 @@
 /** 任务进度列表卡片 — 递归渲染 task_tree */
+import { useMemo, memo } from "react";
 import { ClipboardList, GitBranch, AlertTriangle } from "lucide-react";
 import type { TaskResponse, TaskSummary } from "../../types/api";
 import { TASK_STATUS } from "../../types/api";
@@ -30,7 +31,7 @@ interface TaskNodeProps {
   depth: number;
 }
 
-function TaskNode({ task, depth }: TaskNodeProps) {
+const TaskNode = memo(function TaskNode({ task, depth }: TaskNodeProps) {
   return (
     <>
       <div className="flex items-center gap-3 px-4 py-3 border-t border-gray-50" style={{ paddingLeft: 16 + depth * 16 }}>
@@ -62,19 +63,22 @@ function TaskNode({ task, depth }: TaskNodeProps) {
       ))}
     </>
   );
-}
+});
 
 function countAll(tasks: TaskResponse[]): number {
   return tasks.reduce((s, t) => s + 1 + (t.child_tasks ? countAll(t.child_tasks) : 0), 0);
 }
 
 export default function TaskListCard({ tasks }: TaskListCardProps) {
+  // 🚀 缓存递归计算
+  const totalCount = useMemo(() => countAll(tasks), [tasks]);
+
   return (
     <div className="rounded-xl bg-white shadow-sm">
       <div className="flex items-center gap-2 border-b border-gray-100 px-4 py-3">
         <ClipboardList className="h-5 w-5 text-blue-600" />
         <h3 className="font-semibold text-gray-800">任务流转树</h3>
-        <span className="ml-auto text-xs text-gray-400">{countAll(tasks)} 个任务</span>
+        <span className="ml-auto text-xs text-gray-400">{totalCount} 个任务</span>
       </div>
       {tasks.length === 0 ? (
         <div className="px-4 py-8 text-center text-sm text-gray-400">暂无关联任务</div>

frontend/src/components/ui/LoadingSpinner.tsx

@@ -0,0 +1,10 @@
+import { Loader2 } from "lucide-react";
+
+/** 全局路由懒加载回退组件 */
+export default function LoadingSpinner() {
+  return (
+    <div className="flex items-center justify-center py-32">
+      <Loader2 className="h-8 w-8 animate-spin text-blue-500" />
+    </div>
+  );
+}

frontend/src/components/ui/Toast.tsx

@@ -3,6 +3,7 @@ import {
   useContext,
   useState,
   useCallback,
+  useMemo,
   type ReactNode,
 } from "react";
 import { X, CheckCircle, AlertCircle, Info } from "lucide-react";
@@ -52,8 +53,11 @@ export function ToastProvider({ children }: { children: ReactNode }) {
     }, 3500);
   }, []);
 
+  // 🚀 稳定 Context value 引用
+  const ctxValue = useMemo<ToastContextValue>(() => ({ toast }), [toast]);
+
   return (
-    <ToastContext.Provider value={{ toast }}>
+    <ToastContext.Provider value={ctxValue}>
       {children}
 
       {/* Toast 渲染区 */}

frontend/src/contexts/AuthContext.tsx

@@ -3,6 +3,7 @@ import {
   useContext,
   useState,
   useCallback,
+  useMemo,
   useEffect,
   type ReactNode,
 } from "react";
@@ -107,15 +108,19 @@ export function AuthProvider({ children }: { children: ReactNode }) {
     logoutInternal();
   }, []);
 
+  // 🚀 稳定 Context value 引用，避免消费者不必要的 re-render
+  const ctxValue = useMemo<AuthContextValue>(
+    () => ({
+      ...state,
+      login,
+      logout,
+      isAuthenticated: !!state.token && !!state.user,
+    }),
+    [state, login, logout],
+  );
+
   return (
-    <AuthContext.Provider
+    <AuthContext.Provider value={ctxValue}>
-      value={{
-        ...state,
-        login,
-        logout,
-        isAuthenticated: !!state.token && !!state.user,
-      }}
-    >
       {children}
     </AuthContext.Provider>
   );

frontend/vite.config.ts

@@ -7,6 +7,19 @@ import basicSsl from "@vitejs/plugin-basic-ssl";
 export default defineConfig({
   plugins: [react(), tailwindcss(), basicSsl()],
 
+  // 🚀 构建优化：将第三方巨头独立分包，利用浏览器缓存
+  build: {
+    rollupOptions: {
+      output: {
+        manualChunks: {
+          "vendor-react": ["react", "react-dom", "react-router-dom"],
+          "vendor-antd": ["antd", "@ant-design/icons"],
+          "vendor-qrcode": ["html5-qrcode"],
+        },
+      },
+    },
+  },
+
   clearScreen: false,
   server: {
     host: "0.0.0.0",