test(#352): verify additive source-time migration

docs/02-architecture-and-code-map.md

@@ -2,8 +2,8 @@
 generated: true (请先修改 Gitea Wiki，禁止直接编辑本文件)
 wiki_page: Architecture-and-Code-Map
 wiki_url: https://git.ilapage.cn/OPC/goauto/wiki/Architecture-and-Code-Map.-
-wiki_revision: 88ed799e92f64a73b3bd9472ab6c0b06fa080b37
-synchronized_at: 2026-09-29T09:48:30Z
+wiki_revision: 04a4bcf81f2f2912d101d1aa1c2d8eb802c5719e
+synchronized_at: 2026-09-30T01:50:27Z
 <!-- gitea-wiki-mirror:end -->
 
 <!-- gitea-wiki-mirror:start -->
@@ -137,6 +137,7 @@ Android Portal/Agent
 | 虾皮商品档案增量迁移 | `server/cmd/migrate/migration/version-local/1786700600000_shopee_product_archive.go` |
 | SYB 商品明细导入、解析与虾皮档案合并 | `server/app/goauto/sybimport/`（解析、幂等落库、同步编排、导入端点、管理端 API 和 Admin 页面均已实现） |
 | 顺云宝（SYB）ERP HTTP 客户端与登录会话 | `server/app/goauto/sybclient/`（登录、OCR 验证码、会话缓存、列表与明细读取；见 [SYB-ERP-Interface-Contract](SYB-ERP-Interface-Contract)） |
+| SYB 来源货运单创建时间（#352，待迁移与发布） | `syb_product.syb_stock_created_at` 为可空且带索引的 `t_stock.created`，由 `sybimport/sync.go` 从列表取值，经 `apply.go` 写入；`service.go` 的日期筛选使用该字段。迁移 `server/cmd/migrate/migration/version-local/1789810000000_syb_stock_created_at.go` 仅加列和索引，不改历史行；历史由有界 SYB 重同步补齐。 |
 | SYB 商品明细增量迁移 | `server/cmd/migrate/migration/version-local/1786700700000_syb_product_import.go` |
 | SYB 店铺准入、发现与过滤 | `server/app/goauto/sybshop/`、`server/app/goauto/sybimport/`；迁移 `server/cmd/migrate/migration/version-local/1786700900000_syb_shop.go` |
 | SYB 后台导入任务、进度、单任务互斥与启动恢复 | `server/app/goauto/sybimport/sync_run.go`、`sync_run_handler.go`；表 `syb_sync_run`，迁移 `server/cmd/migrate/migration/version-local/1786701000000_syb_sync_run.go` |

docs/03-business-rules-and-glossary.md

@@ -2,8 +2,8 @@
 generated: true (请先修改 Gitea Wiki，禁止直接编辑本文件)
 wiki_page: Business-Rules-and-Glossary
 wiki_url: https://git.ilapage.cn/OPC/goauto/wiki/Business-Rules-and-Glossary.-
-wiki_revision: 5d9810286d76c52a90902c27a5316f39164f36e0
-synchronized_at: 2026-09-29T09:48:45Z
+wiki_revision: 76037bfdf5e986c478055e7338c21ee1ba561bad
+synchronized_at: 2026-09-30T01:50:31Z
 <!-- gitea-wiki-mirror:end -->
 
 <!-- gitea-wiki-mirror:start -->
@@ -57,6 +57,10 @@ synchronized_at: 2026-09-22T02:56:27Z
 
 ## SYB 商品明细
 
+### 来源创建时间（#352 目标契约，待迁移与发布）
+
+Admin 的「创建时间」范围按 SYB 货运单列表的 `t_stock.created`（UTC+8 本地日期）筛选关联商品明细，起止日均包含；这不是商品明细独立创建时间。同步新增或重同步读取列表 `created` 并存入 `syb_product.syb_stock_created_at`；`syb_product.created_at` 保留 GoAuto 首次入库审计时间。来源值缺失或格式异常时明确报错，不能用订单号或入库时间推断。历史空值不命中日期筛选；迁移后按不超过 31 天且受货运单数量上限约束的区间重同步补齐，先后统计空值数量，失败区间可幂等重跑，仍无法取得来源值的记录保持空值并报告。
+
 - 一行对应 SYB 一条明确的商品/颜色/尺码/数量明细；唯一键为「蝦皮订单号 `code` + 来源明细 `id`」组合，不是全局唯一 ID（未在多货运单样本中验证过全局唯一性）。
 - `productSpec` 自由文本解析：按最后一个逗号切分为颜色/尺码 → 剥离【】备注 → 判断残留分隔符；解析状态分 `success`/`uncertain`/`failed`，永不猜测原文中不存在的颜色或尺码。
 

docs/08-agent-api-contract.md

@@ -2,8 +2,8 @@
 generated: true (请先修改 Gitea Wiki，禁止直接编辑本文件)
 wiki_page: Android-Agent-API-Contract
 wiki_url: https://git.ilapage.cn/OPC/goauto/wiki/Android-Agent-API-Contract.-
-wiki_revision: 18260ec2725eaeb4dcf2543422d58ee4ede8b981
-synchronized_at: 2026-09-29T09:50:08Z
+wiki_revision: f92513e7184fe704d2b9d1c6606b16a86d8d3fb8
+synchronized_at: 2026-09-30T01:58:59Z
 <!-- gitea-wiki-mirror:end -->
 
 <!-- gitea-wiki-mirror:start -->
@@ -89,6 +89,7 @@ PATCH /api/admin/v1/syb-products/{productId}/correction
 
 列表返回结构化字段（`orderCode`、`shopeeItemId`、`productTitle`、`targetColor`、`targetSize`、`quantity`、`unitPriceCent`、`imageUrl`、`parseStatus`、`parseNote`、`manuallyConfirmed`，#340 起另有 `pddPurchaseExcluded`、`excludedRuleId`、`excludedRuleKind`、`excludedRuleKeyword`、`excludedAt`），不含原始 JSON；`purchaseType`（#340）取 `pdd`（默认）/ `excluded` / `all`，其他值 422，与 `processStage`、`createdFrom`/`createdTo` 同时生效；`keyword` 匹配订单号、虾皮商品ID 或商品标题，`parseStatus` 筛选 `success`/`uncertain`/`failed`。详情额外返回 `rawJson`（原始 `details[]` 元素，未做任何改写）。
 
+#352 目标契约（待迁移与发布）：SYB 商品列表沿用 `createdFrom` / `createdTo` 的 `YYYY-MM-DD` 入参和 Admin「创建时间」标签，但条件改为所属货运单 `t_stock.created` 的 UTC+8 日期，使用左闭右开区间并包含结束日。该条件与店铺、订单号、解析状态、处理阶段、采购类型及分页组合；`sybStockCreatedAt` 是新增可空响应字段，来自 `syb_product.syb_stock_created_at`，不等于 GoAuto 审计字段 `createdAt`。历史来源时间为空者在设置日期条件时不返回，不得回退到 `createdAt`；无日期条件仍可返回。
 `reparse` 与 `reparse-batch` 只读取已保存的 `rawJson` 重新执行解析规则，不请求 SYB 接口；请求体 `force` 为 `true` 时才覆盖 `manuallyConfirmed` 的行，默认跳过并在批量结果中标记 `skipped_manual`。批量结果逐条返回 `outcome`（`reparsed` / `skipped_manual` / `unchanged`）与解析状态变化，`ids` 中任何一个不存在都会使整个请求返回错误（与虾皮商品批量删除的"部分成功"语义不同：ID 不存在通常是操作员选错了页面）。
 
 `correction` 提交 `targetColor`、`targetSize`，覆盖解析结果并标记 `manuallyConfirmed=true`；非空的人工修正与解析成功同等可信，会合并进已关联的虾皮商品档案。

server/app/goauto/models/schema.go

@@ -597,6 +597,8 @@ type SYBProduct struct {
 	ExcludedRuleKind    string     `json:"excludedRuleKind,omitempty" gorm:"size:16;not null;default:''"`
 	ExcludedRuleKeyword string     `json:"excludedRuleKeyword,omitempty" gorm:"size:200;not null;default:''"`
 	ExcludedAt          *time.Time `json:"excludedAt,omitempty"`
+	// SYBStockCreatedAt is t_stock.created, not GoAuto's first-import CreatedAt.
+	SYBStockCreatedAt *time.Time `json:"sybStockCreatedAt,omitempty" gorm:"index"`
 
 	CreatedAt time.Time `json:"createdAt"`
 	UpdatedAt time.Time `json:"updatedAt"`

server/app/goauto/sybimport/apply.go

@@ -22,9 +22,10 @@ import (
 // exist in this repo yet — see the package doc), so callers decode SYB's
 // response themselves and hand in only what a detail line requires.
 type OrderInput struct {
-	Code     string // SYB stock/list `code`, e.g. 260728TB95MJTQ
-	StockID  uint64 // SYB stock/list internal `id`, e.g. 75104587
-	ShopName string
+	Code              string // SYB stock/list `code`, e.g. 260728TB95MJTQ
+	StockID           uint64 // SYB stock/list internal `id`, e.g. 75104587
+	ShopName          string
+	SYBStockCreatedAt *time.Time // SYB stock/list `created`; nil for legacy/manual test inputs
 }
 
 // DetailInput mirrors one element of SYB's `details[]` array from
@@ -137,7 +138,8 @@ func ApplyDetail(ctx context.Context, db *gorm.DB, order OrderInput, detail Deta
 
 		record := models.SYBProduct{
 			OrderCode: order.Code, DetailID: detail.ID, StockID: order.StockID, ShopName: order.ShopName,
-			ShopeeItemID: shopeeItemID, ProductTitle: detail.ProductTitle,
+			SYBStockCreatedAt: order.SYBStockCreatedAt,
+			ShopeeItemID:      shopeeItemID, ProductTitle: detail.ProductTitle,
 			TargetColor: parsed.Color, TargetSize: parsed.Size,
 			Quantity: detail.ProductQty, UnitPriceCent: roundCents(detail.ProductPrice),
 			ImageURL:    buildImageURL(detail.ProductThumb),
@@ -191,6 +193,11 @@ func ApplyDetail(ctx context.Context, db *gorm.DB, order OrderInput, detail Deta
 				"quantity": record.Quantity, "unit_price_cent": record.UnitPriceCent, "image_url": record.ImageURL,
 				"parse_status": record.ParseStatus, "parse_note": record.ParseNote, "raw_json": record.RawJSON,
 			}
+			if order.SYBStockCreatedAt != nil {
+				updates["syb_stock_created_at"] = *order.SYBStockCreatedAt
+			} else {
+				record.SYBStockCreatedAt = existing.SYBStockCreatedAt
+			}
 			// An identical re-import keeps a valid AI decision. Changed source,
 			// link, or a newly deterministic parse invalidates it atomically.
 			preserveAI := existing.AIConfirmed && !existing.ManuallyConfirmed && parsed.Status != models.SYBParseStatusSuccess &&

server/app/goauto/sybimport/apply_test.go

@@ -6,6 +6,7 @@ import (
 	"fmt"
 	"strings"
 	"testing"
+	"time"
 
 	"go-admin/app/goauto/migrations"
 	"go-admin/app/goauto/models"
@@ -128,11 +129,15 @@ func TestApplyDetailKeepsMultiUnitQuantityAsOneRow(t *testing.T) {
 func TestApplyDetailIsIdempotentOnOrderCodeAndDetailID(t *testing.T) {
 	db := openTestDB(t)
 	order, detail := realOrder(), realDetailA()
+	firstSource := time.Date(2026, 9, 27, 23, 59, 59, 0, time.FixedZone("SYB", 8*3600))
+	order.SYBStockCreatedAt = &firstSource
 	first, err := sybimport.ApplyDetail(context.Background(), db, order, detail)
 	if err != nil {
 		t.Fatalf("first apply: %v", err)
 	}
 	detail.ProductQty = 2 // simulate the source value changing between imports
+	newSource := firstSource.Add(time.Second)
+	order.SYBStockCreatedAt = &newSource
 	second, err := sybimport.ApplyDetail(context.Background(), db, order, detail)
 	if err != nil {
 		t.Fatalf("second apply: %v", err)
@@ -143,6 +148,13 @@ func TestApplyDetailIsIdempotentOnOrderCodeAndDetailID(t *testing.T) {
 	if second.SYBProduct.ID != first.SYBProduct.ID {
 		t.Fatal("re-import must update the same row, not create a new one")
 	}
+	var stored models.SYBProduct
+	if err := db.First(&stored, first.SYBProduct.ID).Error; err != nil {
+		t.Fatal(err)
+	}
+	if stored.SYBStockCreatedAt == nil || !stored.SYBStockCreatedAt.Equal(newSource) || !stored.CreatedAt.Equal(first.SYBProduct.CreatedAt) {
+		t.Fatalf("re-import must update source time, preserve GoAuto creation: %+v", stored)
+	}
 	var count int64
 	db.Model(&models.SYBProduct{}).Where("order_code = ? AND detail_id = ?", order.Code, detail.ID).Count(&count)
 	if count != 1 {

server/app/goauto/sybimport/service.go

@@ -90,10 +90,10 @@ func (service *Service) List(ctx context.Context, request ListRequest) (ListResp
 		return ListResponse{}, err
 	}
 	if createdFrom != nil {
-		query = query.Where("created_at >= ?", *createdFrom)
+		query = query.Where("syb_stock_created_at >= ?", *createdFrom)
 	}
 	if createdTo != nil {
-		query = query.Where("created_at < ?", *createdTo)
+		query = query.Where("syb_stock_created_at < ?", *createdTo)
 	}
 	if request.ShopName = strings.TrimSpace(request.ShopName); request.ShopName != "" {
 		if len([]rune(request.ShopName)) > 255 {
@@ -179,8 +179,8 @@ func (service *Service) List(ctx context.Context, request ListRequest) (ListResp
 }
 
 // createdAtRange turns inclusive YYYY-MM-DD bounds into a half-open time
-// range. The bounds are interpreted in the server's local timezone, matching
-// the timestamps written by GORM for this service.
+// range. SYB stock.created is an Asia/Shanghai wall-clock timestamp; use that
+// timezone explicitly rather than depending on the server process timezone.
 func createdAtRange(from, to string) (*time.Time, *time.Time, error) {
 	from = strings.TrimSpace(from)
 	to = strings.TrimSpace(to)
@@ -191,7 +191,7 @@ func createdAtRange(from, to string) (*time.Time, *time.Time, error) {
 		if value == "" {
 			return nil, nil
 		}
-		parsed, err := time.ParseInLocation("2006-01-02", value, time.Local)
+		parsed, err := time.ParseInLocation("2006-01-02", value, sybStockLocation)
 		if err != nil {
 			return nil, invalidRequest(label + " 必须是 YYYY-MM-DD")
 		}

server/app/goauto/sybimport/service_test.go

@@ -127,39 +127,58 @@ func TestServiceListCapsPageSizeAt500(t *testing.T) {
 func TestServiceListFiltersByCreatedDateInclusive(t *testing.T) {
 	db := openTestDB(t)
 	order := realOrder()
-	for i, day := range []string{"2026-09-01", "2026-09-02", "2026-09-03"} {
+	for i, stamp := range []string{"2026-09-27 23:59:59", "2026-09-28 00:00:00", "2026-09-29 23:59:59", "2026-09-30 00:00:00"} {
 		rowOrder := order
 		rowOrder.Code = fmt.Sprintf("CREATED-%d", i)
 		rowOrder.StockID += uint64(i)
+		sourceCreated, err := time.ParseInLocation("2006-01-02 15:04:05", stamp, time.FixedZone("SYB", 8*60*60))
+		if err != nil {
+			t.Fatal(err)
+		}
+		rowOrder.SYBStockCreatedAt = &sourceCreated
 		detail := realDetailA()
 		detail.ID += uint64(i)
 		result, err := sybimport.ApplyDetail(context.Background(), db, rowOrder, detail)
 		if err != nil {
 			t.Fatal(err)
 		}
-		created, err := time.ParseInLocation("2006-01-02", day, time.Local)
-		if err != nil {
-			t.Fatal(err)
-		}
-		if err := db.Model(&models.SYBProduct{}).Where("id = ?", result.SYBProduct.ID).Update("created_at", created).Error; err != nil {
+		// Import time must not determine whether the row matches source dates.
+		imported := time.Date(2026, 9, 28, 0, 5, 0, 0, time.FixedZone("SYB", 8*60*60))
+		if err := db.Model(&models.SYBProduct{}).Where("id = ?", result.SYBProduct.ID).Update("created_at", imported).Error; err != nil {
 			t.Fatal(err)
 		}
 	}
+	missing := realOrder()
+	missing.Code = "CREATED-MISSING"
+	missing.StockID += 100
+	missingDetail := realDetailA()
+	missingDetail.ID += 100
+	if _, err := sybimport.ApplyDetail(context.Background(), db, missing, missingDetail); err != nil {
+		t.Fatal(err)
+	}
 	service := sybimport.NewService(db)
 
-	between, err := service.List(context.Background(), sybimport.ListRequest{CreatedFrom: "2026-09-01", CreatedTo: "2026-09-02"})
+	between, err := service.List(context.Background(), sybimport.ListRequest{CreatedFrom: "2026-09-28", CreatedTo: "2026-09-29"})
 	if err != nil || between.Total != 2 {
 		t.Fatalf("inclusive created date range should return two rows, total=%d err=%v", between.Total, err)
 	}
-	fromOnly, err := service.List(context.Background(), sybimport.ListRequest{CreatedFrom: "2026-09-03"})
+	combined, err := service.List(context.Background(), sybimport.ListRequest{
+		CreatedFrom: "2026-09-28", CreatedTo: "2026-09-29", ShopName: order.ShopName,
+		OrderCodes: []string{"CREATED-1", "CREATED-3"}, ParseStatus: models.SYBParseStatusSuccess,
+		Page: 1, PageSize: 1,
+	})
+	if err != nil || combined.Total != 1 || len(combined.Items) != 1 || combined.Items[0].OrderCode != "CREATED-1" {
+		t.Fatalf("date and existing filters must compose before pagination: %+v err=%v", combined, err)
+	}
+	fromOnly, err := service.List(context.Background(), sybimport.ListRequest{CreatedFrom: "2026-09-30"})
 	if err != nil || fromOnly.Total != 1 {
 		t.Fatalf("created-from filter should return one row, total=%d err=%v", fromOnly.Total, err)
 	}
-	toOnly, err := service.List(context.Background(), sybimport.ListRequest{CreatedTo: "2026-09-01"})
+	toOnly, err := service.List(context.Background(), sybimport.ListRequest{CreatedTo: "2026-09-27"})
 	if err != nil || toOnly.Total != 1 {
 		t.Fatalf("created-to filter should return one row, total=%d err=%v", toOnly.Total, err)
 	}
-	if _, err := service.List(context.Background(), sybimport.ListRequest{CreatedFrom: "2026-09-04", CreatedTo: "2026-09-01"}); serviceErrCode(t, err) != sybimport.CodeInvalidRequest {
+	if _, err := service.List(context.Background(), sybimport.ListRequest{CreatedFrom: "2026-09-30", CreatedTo: "2026-09-27"}); serviceErrCode(t, err) != sybimport.CodeInvalidRequest {
 		t.Fatalf("reversed created date range should be rejected: %v", err)
 	}
 }

server/app/goauto/sybimport/sync.go

@@ -45,6 +45,22 @@ const (
 	maxSyncDays = 31
 )
 
+var sybStockLocation = time.FixedZone("SYB UTC+8", 8*60*60)
+
+// parseSYBStockCreatedAt reads the same t_stock.created value used by SYB's
+// date filter. Never derive it from the order code or local import timestamp.
+func parseSYBStockCreatedAt(raw map[string]any) (*time.Time, error) {
+	value, ok := raw["created"].(string)
+	if !ok || strings.TrimSpace(value) == "" {
+		return nil, errors.New("SYB 货运单缺少来源创建时间")
+	}
+	created, err := time.ParseInLocation("2006-01-02 15:04:05", strings.TrimSpace(value), sybStockLocation)
+	if err != nil || created.IsZero() {
+		return nil, errors.New("SYB 货运单来源创建时间格式无效")
+	}
+	return &created, nil
+}
+
 // SyncReport summarises one sync run.
 type SyncReport struct {
 	From string `json:"from"`
@@ -381,14 +397,22 @@ func validateDetailBatch(requested []int64, details []sybclient.StockDetail) err
 // ApplyDetail call and its own transaction — a several-thousand-row sync must
 // not sit in one long-held transaction.
 func applyStockDetail(ctx context.Context, db *gorm.DB, row sybclient.StockRow, detail sybclient.StockDetail, report *SyncReport, sets ...sybproductfilter.RuleSet) error {
+	if row.ID != detail.ID {
+		return fmt.Errorf("货运单列表与明细 ID 不一致: %d/%d", row.ID, detail.ID)
+	}
+	stockCreated, err := parseSYBStockCreatedAt(row.Raw)
+	if err != nil {
+		return fmt.Errorf("货运单 %d: %w", row.ID, err)
+	}
 	var filters sybproductfilter.RuleSet
 	if len(sets) > 0 {
 		filters = sets[0]
 	}
 	order := OrderInput{
-		Code:     detail.Code,
-		StockID:  uint64(detail.ID),
-		ShopName: stringField(row.Raw, "shopName"),
+		Code:              detail.Code,
+		StockID:           uint64(detail.ID),
+		ShopName:          stringField(row.Raw, "shopName"),
+		SYBStockCreatedAt: stockCreated,
 	}
 	if order.Code == "" {
 		order.Code = row.Code

server/app/goauto/sybimport/sync_test.go

@@ -109,6 +109,7 @@ func (f *fakeSYB) server(t *testing.T) *httptest.Server {
 				"id":       float64(1000 + i),
 				"code":     fmt.Sprintf("ORD%s%03d", strings.ReplaceAll(date, "-", ""), i),
 				"shopName": f.shopFor(i),
+				"created":  date + " 10:00:00",
 			})
 		}
 		if f.shortPageAtIndex > 0 && start/pageSize+1 == f.shortPageAtIndex && len(rows) > 0 {
@@ -118,7 +119,7 @@ func (f *fakeSYB) server(t *testing.T) *httptest.Server {
 			if ids := f.pageIDs(date, start, len(f.listCalls)); ids != nil {
 				rows = nil
 				for _, id := range ids {
-					rows = append(rows, map[string]any{"id": id, "code": "TEST", "shopName": f.shopFor(0)})
+					rows = append(rows, map[string]any{"id": id, "code": "TEST", "shopName": f.shopFor(0), "created": date + " 10:00:00"})
 				}
 			}
 		}
@@ -239,6 +240,27 @@ func TestSyncIsIdempotentAcrossRuns(t *testing.T) {
 	if count != 5 {
 		t.Fatalf("重跑不应产生重复行，实际 %d 行", count)
 	}
+	var first models.SYBProduct
+	if err := db.Order("id").First(&first).Error; err != nil {
+		t.Fatal(err)
+	}
+	if first.SYBStockCreatedAt == nil || first.SYBStockCreatedAt.In(sybStockLocation).Format("2006-01-02 15:04:05") != "2026-08-01 10:00:00" {
+		t.Fatalf("source timestamp not saved from stock list: %+v", first.SYBStockCreatedAt)
+	}
+}
+
+func TestParseSYBStockCreatedAtRequiresSourceProof(t *testing.T) {
+	for _, raw := range []map[string]any{nil, {}, {"created": ""}, {"created": "2026/09/28"}, {"created": 123}} {
+		if _, err := parseSYBStockCreatedAt(raw); err == nil {
+			t.Fatalf("invalid source timestamp accepted: %v", raw)
+		}
+	}
+	for _, stamp := range []string{"2026-09-27 23:59:59", "2026-09-28 00:00:00"} {
+		got, err := parseSYBStockCreatedAt(map[string]any{"created": stamp})
+		if err != nil || got.In(sybStockLocation).Format("2006-01-02 15:04:05") != stamp {
+			t.Fatalf("parse %s: %v %v", stamp, got, err)
+		}
+	}
 }
 
 // 超过上限必须在**写库之前**失败，否则会留下一半数据还报错。

server/cmd/migrate/migration/version-local/1789810000000_syb_stock_created_at.go

@@ -0,0 +1,33 @@
+package version_local
+
+import (
+	"runtime"
+
+	"go-admin/app/goauto/models"
+	"go-admin/cmd/migrate/migration"
+	common "go-admin/common/models"
+	"gorm.io/gorm"
+)
+
+// #352 adds the nullable, indexed SYB source timestamp. Historical rows are
+// intentionally left NULL until a bounded SYB re-sync supplies source proof.
+func init() {
+	_, file, _, _ := runtime.Caller(0)
+	migration.Migrate.SetVersion(migration.GetFilename(file), migrateSYBStockCreatedAt)
+}
+
+func migrateSYBStockCreatedAt(db *gorm.DB, version string) error {
+	return db.Transaction(func(tx *gorm.DB) error {
+		if !tx.Migrator().HasColumn(&models.SYBProduct{}, "SYBStockCreatedAt") {
+			if err := tx.Migrator().AddColumn(&models.SYBProduct{}, "SYBStockCreatedAt"); err != nil {
+				return err
+			}
+		}
+		if !tx.Migrator().HasIndex(&models.SYBProduct{}, "SYBStockCreatedAt") {
+			if err := tx.Migrator().CreateIndex(&models.SYBProduct{}, "SYBStockCreatedAt"); err != nil {
+				return err
+			}
+		}
+		return tx.Create(&common.Migration{Version: version}).Error
+	})
+}

server/cmd/migrate/migration/version-local/1789810000000_syb_stock_created_at_test.go

@@ -0,0 +1,43 @@
+package version_local
+
+import (
+	"testing"
+	"time"
+
+	"go-admin/app/goauto/models"
+	common "go-admin/common/models"
+	"gorm.io/driver/sqlite"
+	"gorm.io/gorm"
+)
+
+func TestMigrateSYBStockCreatedAtPreservesLegacyRows(t *testing.T) {
+	db, err := gorm.Open(sqlite.Open("file:syb_stock_created_migration?mode=memory&cache=shared"), &gorm.Config{})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if err := db.Exec("CREATE TABLE syb_product (id integer primary key, created_at datetime)").Error; err != nil {
+		t.Fatal(err)
+	}
+	if err := db.Exec("INSERT INTO syb_product (id, created_at) VALUES (1, '2026-09-28 00:05:00')").Error; err != nil {
+		t.Fatal(err)
+	}
+	if err := db.AutoMigrate(&common.Migration{}); err != nil {
+		t.Fatal(err)
+	}
+	if err := migrateSYBStockCreatedAt(db, "test_syb_stock_created_at"); err != nil {
+		t.Fatal(err)
+	}
+	if !db.Migrator().HasColumn(&models.SYBProduct{}, "SYBStockCreatedAt") || !db.Migrator().HasIndex(&models.SYBProduct{}, "SYBStockCreatedAt") {
+		t.Fatal("migration must add the source time column and index")
+	}
+	var row struct {
+		CreatedAt         time.Time
+		SYBStockCreatedAt *string
+	}
+	if err := db.Table("syb_product").Where("id = 1").Take(&row).Error; err != nil {
+		t.Fatal(err)
+	}
+	if row.CreatedAt.Format("2006-01-02 15:04:05") != "2026-09-28 00:05:00" || row.SYBStockCreatedAt != nil {
+		t.Fatalf("migration must preserve import time and leave source time unknown: %+v", row)
+	}
+}