feat(exporter): 增强SQL构建逻辑以支持供应商信息

在sqlbuilder.go中更新SQL构建逻辑，确保在导出数据时正确关联供应商名称。同时，在fields.go中更新字段标签以反映供应商名称的变化，提升导出数据的准确性和可读性。

server/internal/exporter/sqlbuilder.go

@@ -109,7 +109,8 @@ func BuildSQL(req BuildRequest, whitelist map[string]bool) (string, []interface{
 				continue
 			}
 			if f == "supplier_name" {
-				cols = append(cols, "'' AS `order.supplier_name`")
+				need["supplier"] = true
+				cols = append(cols, "`supplier`.name AS `order.supplier_name`")
 				continue
 			}
 			if f == "is_inner" {

server/internal/schema/fields.go

@@ -252,7 +252,7 @@ func AllLabels() map[string]string {
 		"order.create_time":                        "创建时间",
 		"order.update_time":                        "更新时间",
 		"order.official_price":                     "官方价",
-		"order.merchant_name":                      "分销商名称",
+		"order.merchant_name":                      "客户名称",
 		"order.activity_name":                      "活动名称",
 		"order.goods_name":                         "商品名称",
 		"order.pay_time":                           "支付时间",

server/internal/schema/ymt.go

@@ -69,6 +69,9 @@ func (s ymtSchema) BuildJoins(need map[string]bool, main string) []string {
 	if need["merchant"] {
 		out = append(out, " LEFT JOIN `merchant` ON `merchant`.id = `order_info`.merchant_id")
 	}
+	if need["supplier"] {
+		out = append(out, " LEFT JOIN `supplier` ON `supplier`.id = `order_info`.supplier_id")
+	}
 	if need["activity"] {
 		out = append(out, " LEFT JOIN `activity` ON `activity`.id = `order_info`.activity_id")
 	}