fix(backend): 架构质量改进批次二 (#32-37)

- #32 License 激活迁移到 license_devices 表：Activate/Verify/Deactivate 全部改用
  license_devices，新增 max_devices 校验和 GET /license/devices 端点；
  Activate 现在校验 shop_id 防跨租户激活
- #33 checkInventory 从 StockOutHandler 移到 StockService.CheckInventoryAvailability
- #34 新增 util/response.go 统一错误响应工具（RespondError/RespondSuccess/RespondCreated）
- #35 生产模式 CORS Origin='*' 启动时 Fatal
- #36 生产模式 License 私钥未配置启动时 Fatal
- #37 新增 util/page.go ValidatePageSize，应用到 partner/product/stock_in/stock_out handler

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

backend/internal/handler/license.go

@@ -18,16 +18,19 @@ func NewLicenseHandler(svc *service.LicenseService) *LicenseHandler {
 
 // Activate POST /api/v1/license/activate
 func (h *LicenseHandler) Activate(c *gin.Context) {
+	shopID := middleware.GetShopID(c)
 	var req struct {
 		LicenseKey string `json:"license_key" binding:"required"`
 		DeviceID   string `json:"device_id" binding:"required"`
+		DeviceName string `json:"device_name"`
+		Platform   string `json:"platform"`
 	}
 	if err := c.ShouldBindJSON(&req); err != nil {
 		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
 		return
 	}
 
-	lic, err := h.svc.Activate(req.LicenseKey, req.DeviceID)
+	lic, err := h.svc.Activate(shopID, req.LicenseKey, req.DeviceID, req.DeviceName, req.Platform)
 	if err != nil {
 		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
 		return
@@ -52,7 +55,7 @@ func (h *LicenseHandler) Verify(c *gin.Context) {
 	c.JSON(http.StatusOK, gin.H{"data": lic})
 }
 
-// Info GET /api/v1/license/info — 当前门店授权概况（无需 device_id）
+// Info GET /api/v1/license/info — 当前门店授权概况
 func (h *LicenseHandler) Info(c *gin.Context) {
 	shopID := middleware.GetShopID(c)
 	lic, err := h.svc.ShopInfo(shopID)
@@ -60,17 +63,35 @@ func (h *LicenseHandler) Info(c *gin.Context) {
 		c.JSON(http.StatusOK, gin.H{"data": nil})
 		return
 	}
+
+	var deviceCount int64
+	// count active devices for this shop
+	devs, _ := h.svc.ListDevices(shopID)
+	deviceCount = int64(len(devs))
+
 	phase := middleware.CalcLicensePhase(lic.ExpiresAt)
 	c.JSON(http.StatusOK, gin.H{"data": gin.H{
-		"id":          lic.ID,
-		"type":        lic.Type,
-		"is_active":   lic.IsActive,
-		"max_devices": lic.MaxDevices,
-		"expires_at":  lic.ExpiresAt,
-		"phase":       phase,
+		"id":           lic.ID,
+		"type":         lic.Type,
+		"is_active":    lic.IsActive,
+		"max_devices":  lic.MaxDevices,
+		"device_count": deviceCount,
+		"expires_at":   lic.ExpiresAt,
+		"phase":        phase,
 	}})
 }
 
+// Devices GET /api/v1/license/devices — 已绑定设备列表
+func (h *LicenseHandler) Devices(c *gin.Context) {
+	shopID := middleware.GetShopID(c)
+	devs, err := h.svc.ListDevices(shopID)
+	if err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
+		return
+	}
+	c.JSON(http.StatusOK, gin.H{"data": devs})
+}
+
 // Deactivate POST /api/v1/license/deactivate
 func (h *LicenseHandler) Deactivate(c *gin.Context) {
 	shopID := middleware.GetShopID(c)

backend/internal/handler/license_test.go

@@ -25,16 +25,22 @@ func TestLicenseHandler_Activate_Success(t *testing.T) {
 		LicenseKey: "LHACT-BBBBB-CCCCC-DDDDD",
 		IsActive:   true,
 		ExpiresAt:  &expiry,
+		MaxDevices: 3,
 	}
 	require.NoError(t, db.Create(lic).Error)
 
 	w := makeRequest(r, "POST", "/api/v1/license/activate", token, map[string]interface{}{
 		"license_key": "LHACT-BBBBB-CCCCC-DDDDD",
 		"device_id":   "device-123",
+		"device_name": "Test Machine",
+		"platform":    "windows",
 	})
 	assert.Equal(t, http.StatusOK, w.Code)
-	data := parseResponse(w)["data"].(map[string]interface{})
-	assert.Equal(t, "device-123", data["device_id"])
+
+	// Verify device was recorded in license_devices
+	var dev model.LicenseDevice
+	require.NoError(t, db.Where("license_id = ? AND device_id = ?", lic.ID, "device-123").First(&dev).Error)
+	assert.Equal(t, "Test Machine", dev.DeviceName)
 }
 
 func TestLicenseHandler_Activate_MissingFields(t *testing.T) {
@@ -71,7 +77,7 @@ func TestLicenseHandler_Activate_NotFound(t *testing.T) {
 	assert.Equal(t, http.StatusBadRequest, w.Code)
 }
 
-func TestLicenseHandler_Activate_DeviceMismatch(t *testing.T) {
+func TestLicenseHandler_Activate_DeviceLimitExceeded(t *testing.T) {
 	db := testutil.SetupTestDB()
 	shop := testutil.CreateTestShop(db, "LH004")
 	user := testutil.CreateTestUser(db, shop.ID, "admin", "pass", "admin")
@@ -79,12 +85,13 @@ func TestLicenseHandler_Activate_DeviceMismatch(t *testing.T) {
 	r := setupProtectedRouter(db)
 
 	lic := &model.License{
-		ShopID:     shop.ID,
-		LicenseKey: "LHBND-BBBBB-CCCCC-DDDDD",
-		DeviceID:   "existing-device",
-		IsActive:   true,
+		ShopID: shop.ID, LicenseKey: "LHBND-BBBBB-CCCCC-DDDDD", IsActive: true, MaxDevices: 1,
 	}
 	require.NoError(t, db.Create(lic).Error)
+	// Fill the single allowed slot
+	require.NoError(t, db.Create(&model.LicenseDevice{
+		LicenseID: lic.ID, ShopID: shop.ID, DeviceID: "existing-device",
+	}).Error)
 
 	w := makeRequest(r, "POST", "/api/v1/license/activate", token, map[string]interface{}{
 		"license_key": "LHBND-BBBBB-CCCCC-DDDDD",
@@ -102,10 +109,7 @@ func TestLicenseHandler_Activate_Expired(t *testing.T) {
 
 	expiry := time.Now().Add(-24 * time.Hour)
 	lic := &model.License{
-		ShopID:     shop.ID,
-		LicenseKey: "LHEXP-BBBBB-CCCCC-DDDDD",
-		IsActive:   true,
-		ExpiresAt:  &expiry,
+		ShopID: shop.ID, LicenseKey: "LHEXP-BBBBB-CCCCC-DDDDD", IsActive: true, ExpiresAt: &expiry, MaxDevices: 3,
 	}
 	require.NoError(t, db.Create(lic).Error)
 
@@ -136,18 +140,15 @@ func TestLicenseHandler_Verify_Success(t *testing.T) {
 
 	expiry := time.Now().Add(30 * 24 * time.Hour)
 	lic := &model.License{
-		ShopID:     shop.ID,
-		LicenseKey: "LHVFY-BBBBB-CCCCC-DDDDD",
-		DeviceID:   "my-device",
-		IsActive:   true,
-		ExpiresAt:  &expiry,
+		ShopID: shop.ID, LicenseKey: "LHVFY-BBBBB-CCCCC-DDDDD", IsActive: true, ExpiresAt: &expiry,
 	}
 	require.NoError(t, db.Create(lic).Error)
+	require.NoError(t, db.Create(&model.LicenseDevice{
+		LicenseID: lic.ID, ShopID: shop.ID, DeviceID: "my-device",
+	}).Error)
 
 	w := makeRequest(r, "GET", "/api/v1/license/verify?device_id=my-device", token, nil)
 	assert.Equal(t, http.StatusOK, w.Code)
-	data := parseResponse(w)["data"].(map[string]interface{})
-	assert.Equal(t, "my-device", data["device_id"])
 }
 
 func TestLicenseHandler_Verify_MissingDeviceID(t *testing.T) {
@@ -181,13 +182,12 @@ func TestLicenseHandler_Verify_Expired(t *testing.T) {
 
 	expiry := time.Now().Add(-1 * time.Hour)
 	lic := &model.License{
-		ShopID:     shop.ID,
-		LicenseKey: "LHVEX-BBBBB-CCCCC-DDDDD",
-		DeviceID:   "expired-device",
-		IsActive:   true,
-		ExpiresAt:  &expiry,
+		ShopID: shop.ID, LicenseKey: "LHVEX-BBBBB-CCCCC-DDDDD", IsActive: true, ExpiresAt: &expiry,
 	}
 	require.NoError(t, db.Create(lic).Error)
+	require.NoError(t, db.Create(&model.LicenseDevice{
+		LicenseID: lic.ID, ShopID: shop.ID, DeviceID: "expired-device",
+	}).Error)
 
 	w := makeRequest(r, "GET", "/api/v1/license/verify?device_id=expired-device", token, nil)
 	assert.Equal(t, http.StatusForbidden, w.Code)
@@ -210,18 +210,22 @@ func TestLicenseHandler_Deactivate_Success(t *testing.T) {
 
 	expiry := time.Now().Add(30 * 24 * time.Hour)
 	lic := &model.License{
-		ShopID:     shop.ID,
-		LicenseKey: "LHDAC-BBBBB-CCCCC-DDDDD",
-		DeviceID:   "deactivate-device",
-		IsActive:   true,
-		ExpiresAt:  &expiry,
+		ShopID: shop.ID, LicenseKey: "LHDAC-BBBBB-CCCCC-DDDDD", IsActive: true, ExpiresAt: &expiry,
 	}
 	require.NoError(t, db.Create(lic).Error)
+	require.NoError(t, db.Create(&model.LicenseDevice{
+		LicenseID: lic.ID, ShopID: shop.ID, DeviceID: "deactivate-device",
+	}).Error)
 
 	w := makeRequest(r, "POST", "/api/v1/license/deactivate", token, map[string]interface{}{
 		"device_id": "deactivate-device",
 	})
 	assert.Equal(t, http.StatusOK, w.Code)
+
+	// Verify device was removed
+	var count int64
+	db.Model(&model.LicenseDevice{}).Where("shop_id = ? AND device_id = ?", shop.ID, "deactivate-device").Count(&count)
+	assert.Equal(t, int64(0), count)
 }
 
 func TestLicenseHandler_Deactivate_MissingDeviceID(t *testing.T) {

backend/internal/handler/partner.go

@@ -10,6 +10,7 @@ import (
 
 	"github.com/wangjia/jiu/backend/internal/middleware"
 	"github.com/wangjia/jiu/backend/internal/model"
+	"github.com/wangjia/jiu/backend/internal/util"
 )
 
 type PartnerHandler struct {
@@ -24,6 +25,7 @@ func (h *PartnerHandler) List(c *gin.Context) {
 	shopID := middleware.GetShopID(c)
 	page, _ := strconv.Atoi(c.DefaultQuery("page", "1"))
 	pageSize, _ := strconv.Atoi(c.DefaultQuery("page_size", "20"))
+	pageSize = util.ValidatePageSize(pageSize, 20, 200)
 
 	query := h.db.Model(&model.Partner{}).
 		Where("shop_id = ? AND deleted_at IS NULL", shopID)

backend/internal/handler/product.go

@@ -31,6 +31,7 @@ func (h *ProductHandler) List(c *gin.Context) {
 	shopID := middleware.GetShopID(c)
 	page, _ := strconv.Atoi(c.DefaultQuery("page", "1"))
 	pageSize, _ := strconv.Atoi(c.DefaultQuery("page_size", "20"))
+	pageSize = util.ValidatePageSize(pageSize, 20, 200)
 	keyword := c.Query("keyword")
 	categoryID := c.Query("category_id")
 

backend/internal/handler/stock_in.go

@@ -12,6 +12,7 @@ import (
 	"github.com/wangjia/jiu/backend/internal/middleware"
 	"github.com/wangjia/jiu/backend/internal/model"
 	"github.com/wangjia/jiu/backend/internal/service"
+	"github.com/wangjia/jiu/backend/internal/util"
 )
 
 func timeNow() *time.Time {
@@ -33,6 +34,7 @@ func (h *StockInHandler) List(c *gin.Context) {
 	shopID := middleware.GetShopID(c)
 	page, _ := strconv.Atoi(c.DefaultQuery("page", "1"))
 	pageSize, _ := strconv.Atoi(c.DefaultQuery("page_size", "20"))
+	pageSize = util.ValidatePageSize(pageSize, 20, 200)
 
 	query := h.db.Model(&model.StockInOrder{}).
 		Where("shop_id = ? AND deleted_at IS NULL", shopID)

backend/internal/handler/stock_out.go

@@ -1,7 +1,6 @@
 package handler
 
 import (
-	"fmt"
 	"net/http"
 	"strconv"
 
@@ -11,6 +10,7 @@ import (
 	"github.com/wangjia/jiu/backend/internal/middleware"
 	"github.com/wangjia/jiu/backend/internal/model"
 	"github.com/wangjia/jiu/backend/internal/service"
+	"github.com/wangjia/jiu/backend/internal/util"
 )
 
 type StockOutHandler struct {
@@ -27,6 +27,7 @@ func (h *StockOutHandler) List(c *gin.Context) {
 	shopID := middleware.GetShopID(c)
 	page, _ := strconv.Atoi(c.DefaultQuery("page", "1"))
 	pageSize, _ := strconv.Atoi(c.DefaultQuery("page_size", "20"))
+	pageSize = util.ValidatePageSize(pageSize, 20, 200)
 
 	query := h.db.Model(&model.StockOutOrder{}).
 		Where("shop_id = ? AND deleted_at IS NULL", shopID)
@@ -65,51 +66,6 @@ func (h *StockOutHandler) Get(c *gin.Context) {
 	c.JSON(http.StatusOK, gin.H{"data": order})
 }
 
-// checkInventory validates that warehouse has enough stock for each item (SUM aggregate).
-// warehouseID is the order's warehouse; items are the stock-out line items.
-func (h *StockOutHandler) checkInventory(shopID, warehouseID uint64, items []model.StockOutItem) error {
-	if len(items) == 0 {
-		return nil
-	}
-
-	// Collect product IDs
-	productIDs := make([]uint64, 0, len(items))
-	for _, item := range items {
-		productIDs = append(productIDs, item.ProductID)
-	}
-
-	type inventorySum struct {
-		ProductID uint64
-		Total     float64
-	}
-	var sums []inventorySum
-	h.db.Model(&model.Inventory{}).
-		Select("product_id, COALESCE(SUM(quantity), 0) AS total").
-		Where("shop_id = ? AND warehouse_id = ? AND product_id IN ? AND deleted_at IS NULL",
-			shopID, warehouseID, productIDs).
-		Group("product_id").Scan(&sums)
-
-	// Build map for quick lookup
-	sumMap := make(map[uint64]float64, len(sums))
-	for _, s := range sums {
-		sumMap[s.ProductID] = s.Total
-	}
-
-	for _, item := range items {
-		have := sumMap[item.ProductID]
-		if have < item.Quantity {
-			// Get product name for a clearer error message
-			var p model.Product
-			h.db.Where("id = ?", item.ProductID).First(&p)
-			name := p.Name
-			if name == "" {
-				name = fmt.Sprintf("商品ID %d", item.ProductID)
-			}
-			return fmt.Errorf("库存不足：%s 当前库存 %.0f，需要 %.0f", name, have, item.Quantity)
-		}
-	}
-	return nil
-}
 
 // Create POST /api/v1/stock-out/orders
 func (h *StockOutHandler) Create(c *gin.Context) {
@@ -127,7 +83,7 @@ func (h *StockOutHandler) Create(c *gin.Context) {
 
 	// 状态只允许 draft 或 pending；直接提交审核时校验库存
 	if req.Status == "pending" {
-		if err := h.checkInventory(shopID, req.WarehouseID, req.Items); err != nil {
+		if err := h.stockSvc.CheckInventoryAvailability(shopID, req.WarehouseID, req.Items); err != nil {
 			c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
 			return
 		}
@@ -235,7 +191,7 @@ func (h *StockOutHandler) Submit(c *gin.Context) {
 		c.JSON(http.StatusBadRequest, gin.H{"error": "order not found or not in draft status"})
 		return
 	}
-	if err := h.checkInventory(shopID, order.WarehouseID, order.Items); err != nil {
+	if err := h.stockSvc.CheckInventoryAvailability(shopID, order.WarehouseID, order.Items); err != nil {
 		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
 		return
 	}

backend/internal/router/router.go

@@ -76,6 +76,7 @@ func Setup(r *gin.Engine, db *gorm.DB) {
 		license.POST("/activate", licenseH.Activate)
 		license.GET("/verify", licenseH.Verify)
 		license.POST("/deactivate", licenseH.Deactivate)
+		license.GET("/devices", licenseH.Devices)
 	}
 
 	// 业务路由：ReadOnly + LicenseGuard（过期只读/锁定拦截写操作）

backend/internal/service/license.go

@@ -18,10 +18,11 @@ import (
 )
 
 var (
-	ErrLicenseNotFound = errors.New("license not found")
-	ErrLicenseInactive = errors.New("license is inactive")
-	ErrLicenseExpired  = errors.New("license has expired")
-	ErrDeviceMismatch  = errors.New("license is bound to another device")
+	ErrLicenseNotFound   = errors.New("license not found")
+	ErrLicenseInactive   = errors.New("license is inactive")
+	ErrLicenseExpired    = errors.New("license has expired")
+	ErrDeviceMismatch    = errors.New("license is bound to another device")
+	ErrDeviceLimitExceed = errors.New("device limit reached — deactivate another device first")
 )
 
 type LicenseService struct {
@@ -47,10 +48,12 @@ func GenerateKey(shopID uint64, licenseType string, expiresAt *time.Time) string
 	return fmt.Sprintf("%s-%s-%s-%s", raw[0:5], raw[5:10], raw[10:15], raw[15:20])
 }
 
-// Activate 激活许可证（绑定设备）
-func (s *LicenseService) Activate(licenseKey, deviceID string) (*model.License, error) {
+// Activate 激活许可证并绑定设备到 license_devices 表。
+// 若该设备已绑定，则更新 last_seen_at（幂等）。
+// 若是新设备，则校验是否超出 max_devices 上限。
+func (s *LicenseService) Activate(shopID uint64, licenseKey, deviceID, deviceName, platform string) (*model.License, error) {
 	var lic model.License
-	if err := s.db.Where("license_key = ?", licenseKey).First(&lic).Error; err != nil {
+	if err := s.db.Where("license_key = ? AND shop_id = ?", licenseKey, shopID).First(&lic).Error; err != nil {
 		return nil, ErrLicenseNotFound
 	}
 	if !lic.IsActive {
@@ -59,23 +62,44 @@ func (s *LicenseService) Activate(licenseKey, deviceID string) (*model.License,
 	if lic.ExpiresAt != nil && time.Now().After(*lic.ExpiresAt) {
 		return nil, ErrLicenseExpired
 	}
-	// 若已绑定设备，校验是否一致
-	if lic.DeviceID != "" && lic.DeviceID != deviceID {
-		return nil, ErrDeviceMismatch
+
+	var existing model.LicenseDevice
+	err := s.db.Where("license_id = ? AND device_id = ?", lic.ID, deviceID).First(&existing).Error
+	if err == nil {
+		// Device already bound — just touch last_seen_at (handled by autoUpdateTime)
+		s.db.Model(&existing).Update("device_name", deviceName)
+		return &lic, nil
 	}
 
-	now := time.Now()
-	lic.DeviceID = deviceID
-	lic.ActivatedAt = &now
-	s.db.Save(&lic)
+	// New device — enforce max_devices
+	var count int64
+	s.db.Model(&model.LicenseDevice{}).Where("license_id = ?", lic.ID).Count(&count)
+	if int(count) >= lic.MaxDevices {
+		return nil, ErrDeviceLimitExceed
+	}
+
+	dev := model.LicenseDevice{
+		LicenseID:  lic.ID,
+		ShopID:     shopID,
+		DeviceID:   deviceID,
+		DeviceName: deviceName,
+		Platform:   platform,
+	}
+	if err := s.db.Create(&dev).Error; err != nil {
+		return nil, err
+	}
 	return &lic, nil
 }
 
-// Verify 验证（客户端启动时调用）
+// Verify 验证设备许可证（客户端启动时调用）。
+// 通过 license_devices 表查找设备，再加载对应的许可证做有效性检查。
 func (s *LicenseService) Verify(shopID uint64, deviceID string) (*model.License, error) {
+	var dev model.LicenseDevice
+	if err := s.db.Where("shop_id = ? AND device_id = ?", shopID, deviceID).First(&dev).Error; err != nil {
+		return nil, ErrLicenseNotFound
+	}
 	var lic model.License
-	if err := s.db.Where("shop_id = ? AND device_id = ? AND is_active = 1", shopID, deviceID).
-		First(&lic).Error; err != nil {
+	if err := s.db.Where("id = ? AND is_active = 1", dev.LicenseID).First(&lic).Error; err != nil {
 		return nil, ErrLicenseNotFound
 	}
 	if lic.ExpiresAt != nil && time.Now().After(*lic.ExpiresAt) {
@@ -94,11 +118,19 @@ func (s *LicenseService) ShopInfo(shopID uint64) (*model.License, error) {
 	return &lic, nil
 }
 
-// Deactivate 解绑设备（换机时使用）
+// ListDevices 列出许可证下所有已绑定设备。
+func (s *LicenseService) ListDevices(shopID uint64) ([]model.LicenseDevice, error) {
+	var devs []model.LicenseDevice
+	if err := s.db.Where("shop_id = ?", shopID).Order("activated_at DESC").Find(&devs).Error; err != nil {
+		return nil, err
+	}
+	return devs, nil
+}
+
+// Deactivate 解绑设备（从 license_devices 删除该条记录）。
 func (s *LicenseService) Deactivate(shopID uint64, deviceID string) error {
-	return s.db.Model(&model.License{}).
-		Where("shop_id = ? AND device_id = ?", shopID, deviceID).
-		Updates(map[string]interface{}{"device_id": "", "activated_at": nil}).Error
+	return s.db.Where("shop_id = ? AND device_id = ?", shopID, deviceID).
+		Delete(&model.LicenseDevice{}).Error
 }
 
 // createTrialLicense 在注册事务中为新门店签发 30 天 trial license。

backend/internal/service/license_test.go

@@ -15,71 +15,106 @@ func TestLicenseService_Activate_Success(t *testing.T) {
 	db := testutil.SetupTestDB()
 	shop := testutil.CreateTestShop(db, "LIC001")
 
-	// 创建许可证
 	expiry := time.Now().Add(30 * 24 * time.Hour)
 	lic := &model.License{
-		ShopID:    shop.ID,
+		ShopID:     shop.ID,
 		LicenseKey: "AAAAA-BBBBB-CCCCC-DDDDD",
 		IsActive:   true,
 		ExpiresAt:  &expiry,
+		MaxDevices: 3,
 	}
 	require.NoError(t, db.Create(lic).Error)
 
 	svc := NewLicenseService(db)
-	result, err := svc.Activate("AAAAA-BBBBB-CCCCC-DDDDD", "device-001")
+	result, err := svc.Activate(shop.ID, "AAAAA-BBBBB-CCCCC-DDDDD", "device-001", "Test PC", "windows")
 
 	require.NoError(t, err)
 	require.NotNil(t, result)
-	assert.Equal(t, "device-001", result.DeviceID)
-	assert.NotNil(t, result.ActivatedAt)
+
+	// Verify device record was created
+	var dev model.LicenseDevice
+	require.NoError(t, db.Where("license_id = ? AND device_id = ?", lic.ID, "device-001").First(&dev).Error)
+	assert.Equal(t, "Test PC", dev.DeviceName)
+	assert.Equal(t, "windows", dev.Platform)
 }
 
-func TestLicenseService_Activate_AlreadyBoundToDifferentDevice(t *testing.T) {
+func TestLicenseService_Activate_SameDeviceIdempotent(t *testing.T) {
 	db := testutil.SetupTestDB()
 	shop := testutil.CreateTestShop(db, "LIC002")
 
 	lic := &model.License{
-		ShopID:    shop.ID,
+		ShopID:     shop.ID,
 		LicenseKey: "EEEEE-FFFFF-GGGGG-HHHHH",
-		DeviceID:   "existing-device",
 		IsActive:   true,
+		MaxDevices: 3,
 	}
 	require.NoError(t, db.Create(lic).Error)
+	// Pre-bind the device
+	require.NoError(t, db.Create(&model.LicenseDevice{
+		LicenseID: lic.ID, ShopID: shop.ID, DeviceID: "same-device",
+	}).Error)
 
 	svc := NewLicenseService(db)
-	result, err := svc.Activate("EEEEE-FFFFF-GGGGG-HHHHH", "new-device")
+	// Re-activating same device should succeed (idempotent)
+	result, err := svc.Activate(shop.ID, "EEEEE-FFFFF-GGGGG-HHHHH", "same-device", "Updated Name", "windows")
 
-	assert.Error(t, err)
-	assert.Equal(t, ErrDeviceMismatch, err)
-	assert.Nil(t, result)
+	require.NoError(t, err)
+	require.NotNil(t, result)
+
+	// Still only one device record
+	var count int64
+	db.Model(&model.LicenseDevice{}).Where("license_id = ?", lic.ID).Count(&count)
+	assert.Equal(t, int64(1), count)
 }
 
-func TestLicenseService_Activate_SameDevice(t *testing.T) {
+func TestLicenseService_Activate_DeviceLimitExceeded(t *testing.T) {
 	db := testutil.SetupTestDB()
 	shop := testutil.CreateTestShop(db, "LIC003")
 
 	lic := &model.License{
-		ShopID:    shop.ID,
+		ShopID:     shop.ID,
 		LicenseKey: "IIIII-JJJJJ-KKKKK-LLLLL",
-		DeviceID:   "same-device",
 		IsActive:   true,
+		MaxDevices: 2,
 	}
 	require.NoError(t, db.Create(lic).Error)
+	// Fill up the device limit
+	require.NoError(t, db.Create(&model.LicenseDevice{LicenseID: lic.ID, ShopID: shop.ID, DeviceID: "dev-1"}).Error)
+	require.NoError(t, db.Create(&model.LicenseDevice{LicenseID: lic.ID, ShopID: shop.ID, DeviceID: "dev-2"}).Error)
 
 	svc := NewLicenseService(db)
-	// 同一设备重新激活应该成功
-	result, err := svc.Activate("IIIII-JJJJJ-KKKKK-LLLLL", "same-device")
+	result, err := svc.Activate(shop.ID, "IIIII-JJJJJ-KKKKK-LLLLL", "dev-3", "", "")
 
-	require.NoError(t, err)
-	require.NotNil(t, result)
-	assert.Equal(t, "same-device", result.DeviceID)
+	assert.Error(t, err)
+	assert.Equal(t, ErrDeviceLimitExceed, err)
+	assert.Nil(t, result)
 }
 
 func TestLicenseService_Activate_NotFound(t *testing.T) {
 	db := testutil.SetupTestDB()
+	shop := testutil.CreateTestShop(db, "LIC004")
 
 	svc := NewLicenseService(db)
-	result, err := svc.Activate("NONEX-ISTEN-TTTTT-LICCC", "device-001")
+	result, err := svc.Activate(shop.ID, "NONEX-ISTEN-TTTTT-LICCC", "device-001", "", "")
+
+	assert.Error(t, err)
+	assert.Equal(t, ErrLicenseNotFound, err)
+	assert.Nil(t, result)
+}
+
+func TestLicenseService_Activate_WrongShop(t *testing.T) {
+	db := testutil.SetupTestDB()
+	shop := testutil.CreateTestShop(db, "LIC004B")
+	otherShop := testutil.CreateTestShop(db, "LIC004C")
+
+	lic := &model.License{
+		ShopID: shop.ID, LicenseKey: "OTHSH-BBBBB-CCCCC-DDDDD", IsActive: true, MaxDevices: 3,
+	}
+	require.NoError(t, db.Create(lic).Error)
+
+	svc := NewLicenseService(db)
+	// otherShop cannot activate a license belonging to shop
+	result, err := svc.Activate(otherShop.ID, "OTHSH-BBBBB-CCCCC-DDDDD", "device-001", "", "")
 
 	assert.Error(t, err)
 	assert.Equal(t, ErrLicenseNotFound, err)
@@ -88,20 +123,16 @@ func TestLicenseService_Activate_NotFound(t *testing.T) {
 
 func TestLicenseService_Activate_Inactive(t *testing.T) {
 	db := testutil.SetupTestDB()
-	shop := testutil.CreateTestShop(db, "LIC004")
+	shop := testutil.CreateTestShop(db, "LIC005")
 
-	// 先创建激活的许可证，再禁用（避免 GORM 零值跳过问题）
 	lic := &model.License{
-		ShopID:    shop.ID,
-		LicenseKey: "MMMMM-NNNNN-OOOOO-PPPPP",
-		IsActive:   true,
+		ShopID: shop.ID, LicenseKey: "MMMMM-NNNNN-OOOOO-PPPPP", IsActive: true, MaxDevices: 3,
 	}
 	require.NoError(t, db.Create(lic).Error)
-	// 禁用
 	require.NoError(t, db.Model(lic).Update("is_active", false).Error)
 
 	svc := NewLicenseService(db)
-	result, err := svc.Activate("MMMMM-NNNNN-OOOOO-PPPPP", "device-001")
+	result, err := svc.Activate(shop.ID, "MMMMM-NNNNN-OOOOO-PPPPP", "device-001", "", "")
 
 	assert.Error(t, err)
 	assert.Equal(t, ErrLicenseInactive, err)
@@ -110,20 +141,16 @@ func TestLicenseService_Activate_Inactive(t *testing.T) {
 
 func TestLicenseService_Activate_Expired(t *testing.T) {
 	db := testutil.SetupTestDB()
-	shop := testutil.CreateTestShop(db, "LIC005")
+	shop := testutil.CreateTestShop(db, "LIC006")
 
-	// 已过期
 	expiry := time.Now().Add(-24 * time.Hour)
 	lic := &model.License{
-		ShopID:    shop.ID,
-		LicenseKey: "QQQQQ-RRRRR-SSSSS-TTTTT",
-		IsActive:   true,
-		ExpiresAt:  &expiry,
+		ShopID: shop.ID, LicenseKey: "QQQQQ-RRRRR-SSSSS-TTTTT", IsActive: true, ExpiresAt: &expiry, MaxDevices: 3,
 	}
 	require.NoError(t, db.Create(lic).Error)
 
 	svc := NewLicenseService(db)
-	result, err := svc.Activate("QQQQQ-RRRRR-SSSSS-TTTTT", "device-001")
+	result, err := svc.Activate(shop.ID, "QQQQQ-RRRRR-SSSSS-TTTTT", "device-001", "", "")
 
 	assert.Error(t, err)
 	assert.Equal(t, ErrLicenseExpired, err)
@@ -132,40 +159,37 @@ func TestLicenseService_Activate_Expired(t *testing.T) {
 
 func TestLicenseService_Verify_Success(t *testing.T) {
 	db := testutil.SetupTestDB()
-	shop := testutil.CreateTestShop(db, "LIC006")
+	shop := testutil.CreateTestShop(db, "LIC007")
 
 	expiry := time.Now().Add(30 * 24 * time.Hour)
 	lic := &model.License{
-		ShopID:    shop.ID,
-		LicenseKey: "UUUUU-VVVVV-WWWWW-XXXXX",
-		DeviceID:   "my-device",
-		IsActive:   true,
-		ExpiresAt:  &expiry,
+		ShopID: shop.ID, LicenseKey: "UUUUU-VVVVV-WWWWW-XXXXX", IsActive: true, ExpiresAt: &expiry,
 	}
 	require.NoError(t, db.Create(lic).Error)
+	require.NoError(t, db.Create(&model.LicenseDevice{
+		LicenseID: lic.ID, ShopID: shop.ID, DeviceID: "my-device",
+	}).Error)
 
 	svc := NewLicenseService(db)
 	result, err := svc.Verify(shop.ID, "my-device")
 
 	require.NoError(t, err)
 	require.NotNil(t, result)
-	assert.Equal(t, "my-device", result.DeviceID)
+	assert.Equal(t, lic.ID, result.ID)
 }
 
 func TestLicenseService_Verify_Expired(t *testing.T) {
 	db := testutil.SetupTestDB()
-	shop := testutil.CreateTestShop(db, "LIC007")
+	shop := testutil.CreateTestShop(db, "LIC008")
 
-	// 已过期
 	expiry := time.Now().Add(-1 * time.Hour)
 	lic := &model.License{
-		ShopID:    shop.ID,
-		LicenseKey: "YYYYY-ZZZZZ-AAAAA-BBBBB",
-		DeviceID:   "expired-device",
-		IsActive:   true,
-		ExpiresAt:  &expiry,
+		ShopID: shop.ID, LicenseKey: "YYYYY-ZZZZZ-AAAAA-BBBBB", IsActive: true, ExpiresAt: &expiry,
 	}
 	require.NoError(t, db.Create(lic).Error)
+	require.NoError(t, db.Create(&model.LicenseDevice{
+		LicenseID: lic.ID, ShopID: shop.ID, DeviceID: "expired-device",
+	}).Error)
 
 	svc := NewLicenseService(db)
 	result, err := svc.Verify(shop.ID, "expired-device")
@@ -177,7 +201,7 @@ func TestLicenseService_Verify_Expired(t *testing.T) {
 
 func TestLicenseService_Verify_NotFound(t *testing.T) {
 	db := testutil.SetupTestDB()
-	shop := testutil.CreateTestShop(db, "LIC008")
+	shop := testutil.CreateTestShop(db, "LIC009")
 
 	svc := NewLicenseService(db)
 	result, err := svc.Verify(shop.ID, "nonexistent-device")
@@ -189,17 +213,15 @@ func TestLicenseService_Verify_NotFound(t *testing.T) {
 
 func TestLicenseService_Verify_NoExpiry(t *testing.T) {
 	db := testutil.SetupTestDB()
-	shop := testutil.CreateTestShop(db, "LIC009")
+	shop := testutil.CreateTestShop(db, "LIC010")
 
-	// 永久许可证（无过期时间）
 	lic := &model.License{
-		ShopID:    shop.ID,
-		LicenseKey: "CCCCC-DDDDD-EEEEE-FFFFF",
-		DeviceID:   "lifetime-device",
-		IsActive:   true,
-		ExpiresAt:  nil,
+		ShopID: shop.ID, LicenseKey: "CCCCC-DDDDD-EEEEE-FFFFF", IsActive: true, ExpiresAt: nil,
 	}
 	require.NoError(t, db.Create(lic).Error)
+	require.NoError(t, db.Create(&model.LicenseDevice{
+		LicenseID: lic.ID, ShopID: shop.ID, DeviceID: "lifetime-device",
+	}).Error)
 
 	svc := NewLicenseService(db)
 	result, err := svc.Verify(shop.ID, "lifetime-device")

backend/internal/service/stock.go

@@ -287,3 +287,46 @@ func (s *StockService) GenerateOrderNo(shopID uint64, orderType string) (string,
 	})
 	return no, err
 }
+
+// CheckInventoryAvailability validates that the warehouse has sufficient stock for each item.
+// Returns an error describing the first shortage encountered.
+func (s *StockService) CheckInventoryAvailability(shopID, warehouseID uint64, items []model.StockOutItem) error {
+	if len(items) == 0 {
+		return nil
+	}
+
+	productIDs := make([]uint64, 0, len(items))
+	for _, item := range items {
+		productIDs = append(productIDs, item.ProductID)
+	}
+
+	type inventorySum struct {
+		ProductID uint64
+		Total     float64
+	}
+	var sums []inventorySum
+	s.db.Model(&model.Inventory{}).
+		Select("product_id, COALESCE(SUM(quantity), 0) AS total").
+		Where("shop_id = ? AND warehouse_id = ? AND product_id IN ? AND deleted_at IS NULL",
+			shopID, warehouseID, productIDs).
+		Group("product_id").Scan(&sums)
+
+	sumMap := make(map[uint64]float64, len(sums))
+	for _, s := range sums {
+		sumMap[s.ProductID] = s.Total
+	}
+
+	for _, item := range items {
+		have := sumMap[item.ProductID]
+		if have < item.Quantity {
+			var p model.Product
+			s.db.Where("id = ?", item.ProductID).First(&p)
+			name := p.Name
+			if name == "" {
+				name = fmt.Sprintf("商品ID %d", item.ProductID)
+			}
+			return fmt.Errorf("库存不足：%s 当前库存 %.0f，需要 %.0f", name, have, item.Quantity)
+		}
+	}
+	return nil
+}

backend/internal/util/page.go

@@ -0,0 +1,9 @@
+package util
+
+// ValidatePageSize clamps pageSize into [1, maxSize], returning defaultSize when out of range.
+func ValidatePageSize(pageSize, defaultSize, maxSize int) int {
+	if pageSize < 1 || pageSize > maxSize {
+		return defaultSize
+	}
+	return pageSize
+}

backend/internal/util/response.go

@@ -0,0 +1,22 @@
+package util
+
+import (
+	"net/http"
+
+	"github.com/gin-gonic/gin"
+)
+
+// RespondError writes a structured error response: {"code": code, "message": msg}.
+func RespondError(c *gin.Context, status int, code, msg string) {
+	c.JSON(status, gin.H{"code": code, "message": msg})
+}
+
+// RespondSuccess writes {"data": data} with HTTP 200.
+func RespondSuccess(c *gin.Context, data interface{}) {
+	c.JSON(http.StatusOK, gin.H{"data": data})
+}
+
+// RespondCreated writes {"data": data} with HTTP 201.
+func RespondCreated(c *gin.Context, data interface{}) {
+	c.JSON(http.StatusCreated, gin.H{"data": data})
+}

backend/main.go

@@ -19,6 +19,16 @@ func main() {
 	// 加载配置
 	config.Load()
 
+	// 生产环境启动前置检查
+	if config.C.Server.Mode == "release" {
+		if config.C.Server.CORSOrigin == "*" {
+			log.Fatal("server.cors_origin must not be '*' in production — set it to the actual frontend origin")
+		}
+		if config.C.License.Ed25519PrivateKey == "" {
+			log.Fatal("license.ed25519_private_key is required in production — store the key in Bitwarden and inject via env LICENSE_ED25519PRIVATEKEY")
+		}
+	}
+
 	// 初始化数据库
 	db := initDB()