修复账号删除报错+添加批量删除功能

- 修复单个删除报错：删除账号前先删除关联的LoginTask（外键约束）
- 新增批量删除接口 DELETE /api/accounts/batch/delete
- 路由顺序：/batch/delete 在 /{account_id} 前注册避免路径冲突
- 前端添加批量删除按钮（带确认弹窗）
- 前端添加 batchDelete API

web/frontend/src/api/modules.ts

@@ -53,6 +53,8 @@ export const accountApi = {
     api.put<any, any>('/accounts/batch-tag', { account_ids, tag }),
   listTags: () => api.get<any, string[]>('/accounts/tags/list'),
   delete: (id: number) => api.delete<any, any>(`/accounts/${id}`),
+  batchDelete: (account_ids: number[]) =>
+    api.delete<any, any>('/accounts/batch/delete', { params: { account_ids: account_ids.join(',') } }),
 };
 
 export const loginApi = {

web/frontend/src/pages/AccountsPage.tsx

@@ -150,6 +150,22 @@ export default function AccountsPage() {
     }
   };
 
+  const handleBatchDelete = async () => {
+    if (selectedRowKeys.length === 0) {
+      message.warning('请先选择账号');
+      return;
+    }
+    try {
+      const result = await accountApi.batchDelete(selectedRowKeys as number[]);
+      message.success(result.message);
+      setSelectedRowKeys([]);
+      loadAccounts();
+      loadTags();
+    } catch (e: any) {
+      message.error(e.message);
+    }
+  };
+
   const columns: any[] = [
     { title: 'ID', dataIndex: 'id', width: 60 },
     { title: '用户名', dataIndex: 'username' },
@@ -263,6 +279,24 @@ export default function AccountsPage() {
               >
                 批量打标签
               </Button>
+              {canDelete && (
+                <Popconfirm
+                  title={`确认删除选中的 ${selectedRowKeys.length} 个账号？`}
+                  description="将同时删除关联的登录任务"
+                  onConfirm={handleBatchDelete}
+                  okText="删除"
+                  okButtonProps={{ danger: true }}
+                  cancelText="取消"
+                >
+                  <Button
+                    danger
+                    disabled={selectedRowKeys.length === 0}
+                    icon={<DeleteOutlined />}
+                  >
+                    批量删除
+                  </Button>
+                </Popconfirm>
+              )}
               <Button type="primary" icon={<ImportOutlined />} onClick={() => setImportOpen(true)}>
                 批量导入
               </Button>