修复(#84): 补齐促销管理API实现文件

Co-authored-by: multica-agent <github@multica.ai>

internal/handler/admin/promo/getPromoUsageListHandler.go

@@ -0,0 +1,25 @@
+package promo
+
+import (
+	"github.com/gin-gonic/gin"
+	"github.com/perfect-panel/server/internal/logic/admin/promo"
+	"github.com/perfect-panel/server/internal/svc"
+	"github.com/perfect-panel/server/internal/types"
+	"github.com/perfect-panel/server/pkg/result"
+)
+
+// Get promo usage list
+func GetPromoUsageListHandler(svcCtx *svc.ServiceContext) func(c *gin.Context) {
+	return func(c *gin.Context) {
+		var req types.GetPromoUsageListRequest
+		_ = c.ShouldBind(&req)
+		if err := svcCtx.Validate(&req); err != nil {
+			result.ParamErrorResult(c, err)
+			return
+		}
+
+		l := promo.NewGetPromoUsageListLogic(c.Request.Context(), svcCtx)
+		resp, err := l.GetPromoUsageList(&req)
+		result.HttpResult(c, resp, err)
+	}
+}