fix(admin): 行业选择500修复 + 管理员切换订阅计划

- fix(industry): list_industries SQL参数编号错位 — count查询和items查询
  共用WHERE子句但参数从$3开始，sqlx bind按$1/$2顺序绑定导致500
- feat(billing): 新增 PUT /admin/accounts/:id/subscription 端点 (super_admin)
  验证目标计划 → 取消当前订阅 → 创建新订阅(30天) → 同步配额
- feat(admin-v2): Accounts.tsx 编辑弹窗新增「订阅计划」选择区
  显示所有活跃计划，保存时调用admin switch plan API

admin-v2/src/pages/Accounts.tsx

@@ -9,6 +9,7 @@ import type { ProColumns } from '@ant-design/pro-components'
 import { ProTable } from '@ant-design/pro-components'
 import { accountService } from '@/services/accounts'
 import { industryService } from '@/services/industries'
+import { billingService } from '@/services/billing'
 import { PageHeader } from '@/components/PageHeader'
 import type { AccountPublic } from '@/types'
 
@@ -70,6 +71,12 @@ export default function Accounts() {
     }
   }, [accountIndustries, editingId, form])
 
+  // 获取所有活跃计划（用于管理员切换）
+  const { data: plansData } = useQuery({
+    queryKey: ['billing-plans'],
+    queryFn: ({ signal }) => billingService.listPlans(signal),
+  })
+
   const updateMutation = useMutation({
     mutationFn: ({ id, data }: { id: string; data: Partial<AccountPublic> }) =>
       accountService.update(id, data),
@@ -101,6 +108,14 @@ export default function Accounts() {
     onError: (err: Error) => message.error(err.message || '行业授权更新失败'),
   })
 
+  // 管理员切换用户计划
+  const switchPlanMutation = useMutation({
+    mutationFn: ({ accountId, planId }: { accountId: string; planId: string }) =>
+      billingService.adminSwitchPlan(accountId, planId),
+    onSuccess: () => message.success('计划切换成功'),
+    onError: (err: Error) => message.error(err.message || '计划切换失败'),
+  })
+
   const columns: ProColumns<AccountPublic>[] = [
     { title: '用户名', dataIndex: 'username', width: 120, tooltip: '搜索用户名、邮箱或显示名' },
     { title: '显示名', dataIndex: 'display_name', width: 120, hideInSearch: true },
@@ -186,7 +201,7 @@ export default function Accounts() {
 
     try {
       // 更新基础信息
-      const { industry_ids, ...accountData } = values
+      const { industry_ids, plan_id, ...accountData } = values
       await updateMutation.mutateAsync({ id: editingId, data: accountData })
 
       // 更新行业授权（如果变更了）
@@ -201,6 +216,11 @@ export default function Accounts() {
         queryClient.invalidateQueries({ queryKey: ['account-industries'] })
       }
 
+      // 切换订阅计划（如果选择了新计划）
+      if (plan_id) {
+        await switchPlanMutation.mutateAsync({ accountId: editingId, planId: plan_id })
+      }
+
       handleClose()
     } catch {
       // Errors handled by mutation onError callbacks
@@ -218,6 +238,11 @@ export default function Accounts() {
     label: `${item.icon} ${item.name}`,
   }))
 
+  const planOptions = (plansData || []).map((plan) => ({
+    value: plan.id,
+    label: `${plan.display_name} (¥${(plan.price_cents / 100).toFixed(0)}/月)`,
+  }))
+
   return (
     <div>
       <PageHeader title="账号管理" description="管理系统用户账号、角色、权限与行业授权" />
@@ -256,7 +281,7 @@ export default function Accounts() {
         open={modalOpen}
         onOk={handleSave}
         onCancel={handleClose}
-        confirmLoading={updateMutation.isPending || setIndustriesMutation.isPending}
+        confirmLoading={updateMutation.isPending || setIndustriesMutation.isPending || switchPlanMutation.isPending}
         width={560}
       >
         <Form form={form} layout="vertical" className="mt-4">
@@ -280,6 +305,21 @@ export default function Accounts() {
             ]} />
           </Form.Item>
 
+          <Divider>订阅计划</Divider>
+
+          <Form.Item
+            name="plan_id"
+            label="切换计划"
+            extra="选择新计划后保存将立即切换。留空则不修改当前计划。"
+          >
+            <Select
+              allowClear
+              placeholder="不修改当前计划"
+              options={planOptions}
+              loading={!plansData}
+            />
+          </Form.Item>
+
           <Divider>行业授权</Divider>
 
           <Form.Item

admin-v2/src/services/billing.ts

@@ -90,4 +90,9 @@ export const billingService = {
   getPaymentStatus: (id: string, signal?: AbortSignal) =>
     request.get<PaymentStatus>(`/billing/payments/${id}`, withSignal({}, signal))
       .then((r) => r.data),
+
+  /** 管理员切换用户订阅计划 (super_admin only) */
+  adminSwitchPlan: (accountId: string, planId: string) =>
+    request.put<{ success: boolean; subscription: Subscription }>(`/admin/accounts/${accountId}/subscription`, { plan_id: planId })
+      .then((r) => r.data),
 }