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/AgentTemplates.tsx

@@ -0,0 +1,190 @@
+// ============================================================
+// Agent 模板管理
+// ============================================================
+
+import { useState } from 'react'
+import { useQuery, useMutation, useQueryClient } from '@tanstack/react-query'
+import { Button, message, Tag, Modal, Form, Input, Select, InputNumber, Space, Popconfirm, Descriptions } from 'antd'
+import { PlusOutlined } from '@ant-design/icons'
+import type { ProColumns } from '@ant-design/pro-components'
+import { ProTable } from '@ant-design/pro-components'
+import { agentTemplateService } from '@/services/agent-templates'
+import type { AgentTemplate } from '@/types'
+
+const { TextArea } = Input
+
+const sourceLabels: Record<string, string> = { builtin: '内置', custom: '自定义' }
+const visibilityLabels: Record<string, string> = { public: '公开', team: '团队', private: '私有' }
+const statusLabels: Record<string, string> = { active: '活跃', archived: '已归档' }
+const statusColors: Record<string, string> = { active: 'green', archived: 'default' }
+
+export default function AgentTemplates() {
+  const queryClient = useQueryClient()
+  const [form] = Form.useForm()
+  const [modalOpen, setModalOpen] = useState(false)
+  const [detailRecord, setDetailRecord] = useState<AgentTemplate | null>(null)
+
+  const { data, isLoading } = useQuery({
+    queryKey: ['agent-templates'],
+    queryFn: () => agentTemplateService.list(),
+  })
+
+  const createMutation = useMutation({
+    mutationFn: (data: Parameters<typeof agentTemplateService.create>[0]) =>
+      agentTemplateService.create(data),
+    onSuccess: () => {
+      message.success('创建成功')
+      queryClient.invalidateQueries({ queryKey: ['agent-templates'] })
+      setModalOpen(false)
+      form.resetFields()
+    },
+    onError: (err: Error) => message.error(err.message || '创建失败'),
+  })
+
+  const archiveMutation = useMutation({
+    mutationFn: (id: string) => agentTemplateService.archive(id),
+    onSuccess: () => {
+      message.success('已归档')
+      queryClient.invalidateQueries({ queryKey: ['agent-templates'] })
+    },
+    onError: (err: Error) => message.error(err.message || '归档失败'),
+  })
+
+  const columns: ProColumns<AgentTemplate>[] = [
+    { title: '名称', dataIndex: 'name', width: 160 },
+    { title: '分类', dataIndex: 'category', width: 100 },
+    { title: '模型', dataIndex: 'model', width: 140, render: (_, r) => r.model || '-' },
+    {
+      title: '来源',
+      dataIndex: 'source',
+      width: 80,
+      render: (_, r) => <Tag>{sourceLabels[r.source] || r.source}</Tag>,
+    },
+    {
+      title: '可见性',
+      dataIndex: 'visibility',
+      width: 80,
+      render: (_, r) => <Tag color="blue">{visibilityLabels[r.visibility] || r.visibility}</Tag>,
+    },
+    {
+      title: '状态',
+      dataIndex: 'status',
+      width: 80,
+      render: (_, r) => <Tag color={statusColors[r.status]}>{statusLabels[r.status] || r.status}</Tag>,
+    },
+    { title: '版本', dataIndex: 'current_version', width: 70 },
+    {
+      title: '操作',
+      width: 180,
+      render: (_, record) => (
+        <Space>
+          <Button size="small" onClick={() => setDetailRecord(record)}>详情</Button>
+          {record.status === 'active' && (
+            <Popconfirm title="确定归档此模板？" onConfirm={() => archiveMutation.mutate(record.id)}>
+              <Button size="small" danger>归档</Button>
+            </Popconfirm>
+          )}
+        </Space>
+      ),
+    },
+  ]
+
+  const handleCreate = async () => {
+    const values = await form.validateFields()
+    createMutation.mutate(values)
+  }
+
+  return (
+    <div>
+      <ProTable<AgentTemplate>
+        columns={columns}
+        dataSource={data?.items ?? []}
+        loading={isLoading}
+        rowKey="id"
+        search={false}
+        toolBarRender={() => [
+          <Button key="add" type="primary" icon={<PlusOutlined />} onClick={() => { form.resetFields(); setModalOpen(true) }}>
+            新建模板
+          </Button>,
+        ]}
+        pagination={{
+          total: data?.total ?? 0,
+          pageSize: data?.page_size ?? 20,
+          current: data?.page ?? 1,
+          showSizeChanger: false,
+        }}
+      />
+
+      <Modal
+        title="新建 Agent 模板"
+        open={modalOpen}
+        onOk={handleCreate}
+        onCancel={() => { setModalOpen(false); form.resetFields() }}
+        confirmLoading={createMutation.isPending}
+        width={640}
+      >
+        <Form form={form} layout="vertical">
+          <Form.Item name="name" label="名称" rules={[{ required: true }]}>
+            <Input />
+          </Form.Item>
+          <Form.Item name="description" label="描述">
+            <TextArea rows={2} />
+          </Form.Item>
+          <Form.Item name="category" label="分类">
+            <Input placeholder="如 assistant, tool" />
+          </Form.Item>
+          <Form.Item name="model" label="默认模型">
+            <Input placeholder="如 gpt-4o" />
+          </Form.Item>
+          <Form.Item name="system_prompt" label="系统提示词">
+            <TextArea rows={4} />
+          </Form.Item>
+          <Form.Item name="temperature" label="Temperature">
+            <InputNumber min={0} max={2} step={0.1} style={{ width: '100%' }} />
+          </Form.Item>
+          <Form.Item name="max_tokens" label="最大 Token">
+            <InputNumber min={1} style={{ width: '100%' }} />
+          </Form.Item>
+          <Form.Item name="visibility" label="可见性">
+            <Select options={[
+              { value: 'public', label: '公开' },
+              { value: 'team', label: '团队' },
+              { value: 'private', label: '私有' },
+            ]} />
+          </Form.Item>
+        </Form>
+      </Modal>
+
+      <Modal
+        title="模板详情"
+        open={!!detailRecord}
+        onCancel={() => setDetailRecord(null)}
+        footer={null}
+        width={640}
+      >
+        {detailRecord && (
+          <Descriptions column={2} bordered size="small">
+            <Descriptions.Item label="名称">{detailRecord.name}</Descriptions.Item>
+            <Descriptions.Item label="分类">{detailRecord.category}</Descriptions.Item>
+            <Descriptions.Item label="模型">{detailRecord.model || '-'}</Descriptions.Item>
+            <Descriptions.Item label="来源">{sourceLabels[detailRecord.source]}</Descriptions.Item>
+            <Descriptions.Item label="可见性">{visibilityLabels[detailRecord.visibility]}</Descriptions.Item>
+            <Descriptions.Item label="状态">{statusLabels[detailRecord.status]}</Descriptions.Item>
+            <Descriptions.Item label="描述" span={2}>{detailRecord.description || '-'}</Descriptions.Item>
+            <Descriptions.Item label="系统提示词" span={2}>
+              <div style={{ whiteSpace: 'pre-wrap', maxHeight: 200, overflow: 'auto' }}>
+                {detailRecord.system_prompt || '-'}
+              </div>
+            </Descriptions.Item>
+            <Descriptions.Item label="工具" span={2}>
+              {detailRecord.tools?.map((t) => <Tag key={t}>{t}</Tag>) || '-'}
+            </Descriptions.Item>
+            <Descriptions.Item label="能力" span={2}>
+              {detailRecord.capabilities?.map((c) => <Tag key={c} color="blue">{c}</Tag>) || '-'}
+            </Descriptions.Item>
+          </Descriptions>
+        )}
+      </Modal>
+    </div>
+  )
+}