refactor(admin): 合并管理后台并移除 apps/agent

- 平台与代理共用 apps/admin，统一登录 manage/auth/login
- 按 userType 展示菜单，修复 token 循环跳转
- 删除独立 apps/agent 前端工程

Co-authored-by: Cursor <cursoragent@cursor.com>

apps/admin/src/layouts/ManageLayout.vue

@@ -0,0 +1,65 @@
+<script setup lang="ts">
+import { computed } from 'vue';
+import { RouterView, RouterLink, useRoute, useRouter } from 'vue-router';
+import { useAuthStore } from '../stores/auth';
+
+const route = useRoute();
+const router = useRouter();
+const auth = useAuthStore();
+
+const adminMenus = [
+  { path: '/', label: '控制台' },
+  { path: '/users', label: '玩家管理' },
+  { path: '/agents', label: '代理管理' },
+  { path: '/matches', label: '赛事管理' },
+  { path: '/bets', label: '注单管理' },
+  { path: '/cashback', label: '返水管理' },
+  { path: '/audit', label: '操作日志' },
+];
+
+const agentMenus = [
+  { path: '/', label: '概览' },
+  { path: '/my-players', label: '直属玩家' },
+  { path: '/sub-agents', label: '下级代理' },
+  { path: '/my-bets', label: '注单查询' },
+];
+
+const menus = computed(() => (auth.isAdmin.value ? adminMenus : agentMenus));
+
+function logout() {
+  auth.logout();
+  router.push('/login');
+}
+</script>
+
+<template>
+  <el-container style="min-height: 100vh">
+    <el-aside width="200px" style="background: #1a2332">
+      <div style="padding: 20px">
+        <img src="/logo.png" alt="TheBet365" style="height: 56px; width: auto; display: block" />
+        <div style="margin-top: 8px; font-size: 12px; color: #888">{{ auth.portalLabel }}</div>
+        <div v-if="auth.user" style="margin-top: 6px; font-size: 12px; color: #aaa">
+          {{ auth.user.username }}
+        </div>
+      </div>
+      <el-menu
+        background-color="#1a2332"
+        text-color="#ccc"
+        active-text-color="#00a826"
+        :default-active="route.path"
+      >
+        <el-menu-item v-for="m in menus" :key="m.path" :index="m.path">
+          <RouterLink :to="m.path" style="color: inherit; width: 100%">{{ m.label }}</RouterLink>
+        </el-menu-item>
+      </el-menu>
+    </el-aside>
+    <el-container>
+      <el-header
+        style="display: flex; justify-content: flex-end; align-items: center; border-bottom: 1px solid #eee"
+      >
+        <el-button @click="logout">退出</el-button>
+      </el-header>
+      <el-main><RouterView /></el-main>
+    </el-container>
+  </el-container>
+</template>