refactor: 一次性佣金配置从套餐级别提升到系列级别

主要变更:
- 新增 tb_shop_series_allocation 表，存储系列级别的一次性佣金配置
- ShopPackageAllocation 移除 one_time_commission_amount 字段
- PackageSeries 新增 enable_one_time_commission 字段控制是否启用一次性佣金
- 新增 /api/admin/shop-series-allocations CRUD 接口
- 佣金计算逻辑改为从 ShopSeriesAllocation 获取一次性佣金金额
- 删除废弃的 ShopSeriesOneTimeCommissionTier 模型
- OpenAPI Tag '系列分配' 和 '单套餐分配' 合并为 '套餐分配'

迁移脚本:
- 000042: 重构佣金套餐模型
- 000043: 简化佣金分配
- 000044: 一次性佣金分配重构
- 000045: PackageSeries 添加 enable_one_time_commission 字段

测试:
- 新增验收测试 (shop_series_allocation, commission_calculation)
- 新增流程测试 (one_time_commission_chain)
- 删除过时的单元测试（已被验收测试覆盖）

tests/integration/iot_card_test.go

@@ -672,7 +672,6 @@ func TestIotCard_BatchSetSeriesBinding(t *testing.T) {
 		// 创建一个禁用的分配
 		disabledSeries := createTestPackageSeries(t, env, "禁用系列")
 		env.TX.Model(&model.PackageSeries{}).Where("id = ?", disabledSeries.ID).Update("status", constants.StatusDisabled)
-		env.TX.Model(&model.ShopSeriesAllocation{}).Where("id = ?", disabledSeries.ID).Update("status", constants.StatusDisabled)
 
 		body := map[string]interface{}{
 			"iccids":    []string{cards[2].ICCID},
@@ -799,3 +798,64 @@ func TestIotCard_BatchSetSeriesBinding(t *testing.T) {
 		}
 	})
 }
+
+func createTestPackageSeries(t *testing.T, env *integ.IntegrationTestEnv, name string) *model.PackageSeries {
+	t.Helper()
+
+	timestamp := time.Now().UnixNano()
+	series := &model.PackageSeries{
+		SeriesCode: fmt.Sprintf("SERIES_%d", timestamp),
+		SeriesName: name,
+		Status:     constants.StatusEnabled,
+		BaseModel: model.BaseModel{
+			Creator: 1,
+			Updater: 1,
+		},
+	}
+
+	err := env.TX.Create(series).Error
+	require.NoError(t, err, "创建测试套餐系列失败")
+
+	return series
+}
+
+func createTestAllocation(t *testing.T, env *integ.IntegrationTestEnv, shopID, seriesID, allocatorShopID uint) *model.ShopPackageAllocation {
+	t.Helper()
+
+	timestamp := time.Now().UnixNano()
+	pkg := &model.Package{
+		PackageCode:          fmt.Sprintf("PKG_%d", timestamp),
+		PackageName:          "测试套餐",
+		SeriesID:             seriesID,
+		PackageType:          "formal",
+		DurationMonths:       1,
+		RealDataMB:           1024,
+		CostPrice:            5000,
+		SuggestedRetailPrice: 12800,
+		Status:               constants.StatusEnabled,
+		ShelfStatus:          1,
+		BaseModel: model.BaseModel{
+			Creator: 1,
+			Updater: 1,
+		},
+	}
+	err := env.TX.Create(pkg).Error
+	require.NoError(t, err, "创建测试套餐失败")
+
+	allocation := &model.ShopPackageAllocation{
+		ShopID:          shopID,
+		PackageID:       pkg.ID,
+		AllocatorShopID: allocatorShopID,
+		CostPrice:       5000,
+		Status:          constants.StatusEnabled,
+		BaseModel: model.BaseModel{
+			Creator: 1,
+			Updater: 1,
+		},
+	}
+
+	err = env.TX.Create(allocation).Error
+	require.NoError(t, err, "创建测试分配失败")
+
+	return allocation
+}