fix: 完善用户路由和注册回调

- App.tsx 导入 hasValidUserSession 修复 TS 编译错误
- UserRegister 增加 onLogin 回调，注册成功自动跳转

src/web/App.tsx

@@ -5,7 +5,7 @@ import SearchModal from './components/SearchModal.js';
 import NotificationPanel from './components/NotificationPanel.js';
 import TooltipLayer from './components/TooltipLayer.js';
 import { api } from './api.js';
-import { clearAuthSession, hasValidAuthSession, persistAuthSession } from './authSession.js';
+import { clearAuthSession, hasValidAuthSession, hasValidUserSession, persistAuthSession } from './authSession.js';
 import {
   FIRST_USE_DOC_REMINDER_KEY,
   LEGACY_THEME_STORAGE_KEY,
@@ -735,6 +735,10 @@ function AppShell() {
   const isUserPage = location.pathname.startsWith('/user/');
   const isPublicUserPage = ['/user/login', '/user/register'].includes(location.pathname);
 
+  if (isUserPage && isPublicUserPage && userAuthed) {
+    return <Navigate to="/user/dashboard" />;
+  }
+
   if (!authed && !isUserPage) {
     return <Login t={t} onLogin={(token) => {
       persistAuthSession(localStorage, token);
@@ -751,7 +755,7 @@ function AppShell() {
       <Suspense fallback={<RouteLoadingFallback />}>
         <Routes>
           <Route path="/user/login" element={<UserLogin onLogin={() => setUserAuthed(true)} />} />
-          <Route path="/user/register" element={<UserRegister />} />
+          <Route path="/user/register" element={<UserRegister onLogin={() => setUserAuthed(true)} />} />
         </Routes>
       </Suspense>
     );

src/web/pages/UserRegister.tsx

@@ -2,7 +2,7 @@ import React, { useState } from 'react';
 import { useNavigate, Link } from 'react-router-dom';
 import { persistUserSession } from '../authSession.js';
 
-export default function UserRegister() {
+export default function UserRegister({ onLogin }: { onLogin?: () => void }) {
   const navigate = useNavigate();
   const [username, setUsername] = useState('');
   const [email, setEmail] = useState('');
@@ -36,6 +36,7 @@ export default function UserRegister() {
       }
       const result = await res.json();
       persistUserSession(localStorage, result.token);
+      onLogin?.();
       navigate('/user/dashboard');
     } catch (err: any) {
       setError(err?.message || '注册失败');