feat(admin): Admin V2 — Ant Design Pro 纯 SPA 重写

Next.js SSR/hydration 与 SWR fetch-on-mount 存在根本冲突：
hydration 卸载组件时 abort 的请求仍占用后端 DB 连接，
retry 循环耗尽 PostgreSQL 连接池导致后端完全卡死。

admin-v2 使用 Vite + React + antd 纯 SPA 彻底消除此问题：
- 12 页面全部完成（Login, Dashboard, Accounts, Providers, Models,
  API Keys, Usage, Relay, Config, Prompts, Logs, Agent Templates）
- ProTable + ProForm + ProLayout 统一 UI 模式
- TanStack Query + Axios + Zustand 数据层
- JWT 自动刷新 + 401 重试机制
- 全部 18 网络请求 200 OK，零 ERR_ABORTED

同时更新 troubleshooting 第 13 节和 SaaS 平台文档。

admin-v2/src/pages/Logs.tsx

@@ -0,0 +1,112 @@
+// ============================================================
+// 操作日志
+// ============================================================
+
+import { useState } from 'react'
+import { useQuery } from '@tanstack/react-query'
+import { Tag, Select, Typography } from 'antd'
+import type { ProColumns } from '@ant-design/pro-components'
+import { ProTable } from '@ant-design/pro-components'
+import { logService } from '@/services/logs'
+import type { OperationLog } from '@/types'
+
+const { Title } = Typography
+
+const actionLabels: Record<string, string> = {
+  login: '登录', logout: '登出',
+  create_account: '创建账号', update_account: '更新账号', delete_account: '删除账号',
+  create_provider: '创建服务商', update_provider: '更新服务商', delete_provider: '删除服务商',
+  create_model: '创建模型', update_model: '更新模型', delete_model: '删除模型',
+  create_token: '创建密钥', revoke_token: '撤销密钥',
+  update_config: '更新配置',
+  create_prompt: '创建提示词', update_prompt: '更新提示词', archive_prompt: '归档提示词',
+  desktop_audit: '桌面端审计',
+}
+
+const actionColors: Record<string, string> = {
+  login: 'green', logout: 'default',
+  create_account: 'blue', update_account: 'orange', delete_account: 'red',
+  create_provider: 'blue', update_provider: 'orange', delete_provider: 'red',
+  create_model: 'blue', update_model: 'orange', delete_model: 'red',
+  create_token: 'blue', revoke_token: 'red',
+  update_config: 'orange',
+  create_prompt: 'blue', update_prompt: 'orange', archive_prompt: 'red',
+  desktop_audit: 'default',
+}
+
+const actionOptions = Object.entries(actionLabels).map(([value, label]) => ({ value, label }))
+
+export default function Logs() {
+  const [page, setPage] = useState(1)
+  const [actionFilter, setActionFilter] = useState<string | undefined>(undefined)
+
+  const { data, isLoading } = useQuery({
+    queryKey: ['logs', page, actionFilter],
+    queryFn: () => logService.list({ page, page_size: 20, action: actionFilter }),
+  })
+
+  const columns: ProColumns<OperationLog>[] = [
+    {
+      title: '操作类型',
+      dataIndex: 'action',
+      width: 140,
+      render: (_, r) => (
+        <Tag color={actionColors[r.action] || 'default'}>
+          {actionLabels[r.action] || r.action}
+        </Tag>
+      ),
+    },
+    { title: '目标类型', dataIndex: 'target_type', width: 100, render: (_, r) => r.target_type || '-' },
+    { title: '目标 ID', dataIndex: 'target_id', width: 120, render: (_, r) => r.target_id ? <code>{r.target_id.substring(0, 8)}...</code> : '-' },
+    {
+      title: '详情',
+      dataIndex: 'details',
+      width: 250,
+      ellipsis: true,
+      render: (_, r) => {
+        if (!r.details) return '-'
+        if (typeof r.details === 'string') return r.details
+        return JSON.stringify(r.details)
+      },
+    },
+    { title: 'IP 地址', dataIndex: 'ip_address', width: 130, render: (_, r) => <code>{r.ip_address || '-'}</code> },
+    {
+      title: '时间',
+      dataIndex: 'created_at',
+      width: 180,
+      render: (_, r) => new Date(r.created_at).toLocaleString('zh-CN'),
+    },
+  ]
+
+  return (
+    <div>
+      <div style={{ display: 'flex', justifyContent: 'space-between', alignItems: 'center', marginBottom: 24 }}>
+        <Title level={4} style={{ margin: 0 }}>操作日志</Title>
+        <Select
+          value={actionFilter}
+          onChange={(v) => { setActionFilter(v === 'all' ? undefined : v); setPage(1) }}
+          placeholder="操作类型筛选"
+          style={{ width: 160 }}
+          allowClear
+          options={[{ value: 'all', label: '全部操作' }, ...actionOptions]}
+        />
+      </div>
+
+      <ProTable<OperationLog>
+        columns={columns}
+        dataSource={data?.items ?? []}
+        loading={isLoading}
+        rowKey="id"
+        search={false}
+        toolBarRender={false}
+        pagination={{
+          total: data?.total ?? 0,
+          pageSize: 20,
+          current: page,
+          onChange: setPage,
+          showSizeChanger: false,
+        }}
+      />
+    </div>
+  )
+}