feat(frontend): S0 Vue3 脚手架 + auth + Layout shell（4入口，模拟/实盘灰显）

- Vite+TS+ElementPlus+ECharts+Pinia+Router+Axios
- auth store + JWT axios 拦截器 + 路由守卫
- 登录页 + Layout（侧栏 4 入口，回测/投研 active，模拟/实盘 disabled）
- 占位页（backtest/factor，S1/S2 填充）
- vitest auth store 3 tests passed + build 通过(dist 生成)

frontend/src/views/Layout.vue

@@ -0,0 +1,99 @@
+<script setup lang="ts">
+import { useRouter } from 'vue-router'
+import { useAuthStore } from '@/stores/auth'
+
+const router = useRouter()
+const auth = useAuthStore()
+
+function navigate(path: string): void {
+  router.push(path)
+}
+
+function onLogout(): void {
+  auth.logout()
+  router.push('/login')
+}
+</script>
+
+<template>
+  <el-container class="layout">
+    <el-aside width="200px" class="sidebar">
+      <div class="logo">三国量化</div>
+      <el-menu :default-active="$route.path" @select="navigate">
+        <el-menu-item index="/backtest/new">
+          <span>📊 回测</span>
+        </el-menu-item>
+        <el-menu-item index="/factor/new">
+          <span>🔬 投研</span>
+        </el-menu-item>
+        <el-menu-item index="sim" disabled>
+          <span>🧪 模拟 <em class="muted">（C 期）</em></span>
+        </el-menu-item>
+        <el-menu-item index="live" disabled>
+          <span>💰 实盘 <em class="muted">（D 期 · 国金 QMT）</em></span>
+        </el-menu-item>
+      </el-menu>
+    </el-aside>
+    <el-container>
+      <el-header class="header">
+        <span class="sys-name">投研 + 回测 控制台</span>
+        <div class="user-area">
+          <span>{{ auth.username }}</span>
+          <el-button link type="primary" @click="onLogout">登出</el-button>
+        </div>
+      </el-header>
+      <el-main>
+        <router-view />
+      </el-main>
+    </el-container>
+  </el-container>
+</template>
+
+<style scoped>
+.layout {
+  height: 100vh;
+}
+.sidebar {
+  background: #001529;
+  color: #fff;
+}
+.logo {
+  height: 60px;
+  line-height: 60px;
+  text-align: center;
+  font-size: 18px;
+  color: #fff;
+  background: #002140;
+}
+.header {
+  display: flex;
+  align-items: center;
+  justify-content: space-between;
+  background: #fff;
+  border-bottom: 1px solid #eee;
+}
+.sys-name {
+  font-weight: 600;
+}
+.user-area {
+  display: flex;
+  align-items: center;
+  gap: 12px;
+}
+.muted {
+  color: #999;
+  font-style: normal;
+  font-size: 12px;
+}
+:deep(.el-menu) {
+  background: transparent;
+  border-right: none;
+}
+:deep(.el-menu-item) {
+  color: #ccc;
+}
+:deep(.el-menu-item.is-active) {
+  color: #fff;
+  background: #1890ff;
+}
+</style>

frontend/src/views/Login.vue

@@ -0,0 +1,69 @@
+<script setup lang="ts">
+import { ref, reactive } from 'vue'
+import { useRouter } from 'vue-router'
+import { ElMessage } from 'element-plus'
+import { apiClient } from '@/api/client'
+import { useAuthStore } from '@/stores/auth'
+
+const router = useRouter()
+const auth = useAuthStore()
+
+const loading = ref(false)
+const form = reactive({ username: 'admin', password: '' })
+
+async function onSubmit(): Promise<void> {
+  if (!form.username || !form.password) {
+    ElMessage.warning('请输入用户名和密码')
+    return
+  }
+  loading.value = true
+  try {
+    const { data } = await apiClient.post<{ token: string }>('/auth/login', {
+      username: form.username,
+      password: form.password,
+    })
+    auth.setToken(data.token, form.username)
+    router.push('/')
+  } catch {
+    ElMessage.error('登录失败：用户名或密码错误')
+  } finally {
+    loading.value = false
+  }
+}
+</script>
+
+<template>
+  <div class="login-wrap">
+    <el-card class="login-card">
+      <template #header>
+        <h2 class="login-title">三国量化研究台</h2>
+      </template>
+      <el-form label-position="top" @submit.prevent="onSubmit">
+        <el-form-item label="用户名">
+          <el-input v-model="form.username" placeholder="admin" />
+        </el-form-item>
+        <el-form-item label="密码">
+          <el-input v-model="form.password" type="password" show-password placeholder="请输入密码" @keyup.enter="onSubmit" />
+        </el-form-item>
+        <el-button type="primary" :loading="loading" style="width: 100%" @click="onSubmit">登录</el-button>
+      </el-form>
+    </el-card>
+  </div>
+</template>
+
+<style scoped>
+.login-wrap {
+  height: 100vh;
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  background: #f0f2f5;
+}
+.login-card {
+  width: 360px;
+}
+.login-title {
+  margin: 0;
+  text-align: center;
+}
+</style>

frontend/src/views/backtest/New.vue

@@ -0,0 +1,4 @@
+<script setup lang="ts"></script>
+<template>
+  <el-empty description="回测 - 新建（S1 切片实现）" />
+</template>

frontend/src/views/backtest/Progress.vue

@@ -0,0 +1,4 @@
+<script setup lang="ts"></script>
+<template>
+  <el-empty description="回测 - 进度（S1 切片实现）" />
+</template>

frontend/src/views/backtest/Result.vue

@@ -0,0 +1,4 @@
+<script setup lang="ts"></script>
+<template>
+  <el-empty description="回测 - 结果（S1 切片实现）" />
+</template>

frontend/src/views/factor/New.vue

@@ -0,0 +1,4 @@
+<script setup lang="ts"></script>
+<template>
+  <el-empty description="投研 - 新建因子分析（S2 切片实现）" />
+</template>

frontend/src/views/factor/Result.vue

@@ -0,0 +1,4 @@
+<script setup lang="ts"></script>
+<template>
+  <el-empty description="投研 - 结果（S2 切片实现）" />
+</template>