feat: sn

openspec/changes/update-device-batch-import-contract/specs/device-batch-import/spec.md

@@ -0,0 +1,21 @@
+# Device Batch Import Specification
+
+## ADDED Requirements
+
+### Requirement: Admin device import template includes optional sn after virtual_no
+
+The admin device import template SHALL insert an optional `sn` column immediately after required `virtual_no`.
+
+#### Scenario: Download the latest device import template
+
+- **GIVEN** a platform user opens the "批量导入设备" dialog
+- **WHEN** the user clicks "下载导入模板"
+- **THEN** the downloaded template MUST include `virtual_no` as the first column
+- **AND** the downloaded template MUST include `sn` as the second column
+- **AND** `sn` MUST be optional
+
+#### Scenario: Import dialog documents the new sn column
+
+- **GIVEN** a platform user opens the "批量导入设备" dialog
+- **WHEN** the import instructions are displayed
+- **THEN** the page MUST indicate that `sn` is an optional column in the device import template