feat(订阅): 添加节点数量统计功能

在订阅数据结构中新增node_count字段，用于统计符合条件的节点数量
实现根据节点ID和标签计算启用节点数量的逻辑

internal/logic/public/portal/getSubscriptionLogic.go

@@ -3,6 +3,7 @@ package portal
 import (
 	"context"
 	"encoding/json"
+	"strings"
 
 	"github.com/perfect-panel/server/internal/model/subscribe"
 	"github.com/perfect-panel/server/internal/svc"
@@ -52,8 +53,28 @@ func (l *GetSubscriptionLogic) GetSubscription(req *types.GetSubscriptionRequest
 			var discount []types.SubscribeDiscount
 			_ = json.Unmarshal([]byte(item.Discount), &discount)
 			sub.Discount = discount
-			list[i] = sub
 		}
+		
+		// 计算节点数量
+		nodeIds := tool.StringToInt64Slice(item.Nodes)
+		var nodeTags []string
+		if item.NodeTags != "" {
+			tags := strings.Split(item.NodeTags, ",")
+			for _, tag := range tags {
+				if strings.TrimSpace(tag) != "" {
+					nodeTags = append(nodeTags, strings.TrimSpace(tag))
+				}
+			}
+		}
+		
+		nodeCount, err := l.svcCtx.NodeModel.CountNodesByIdsAndTags(l.ctx, nodeIds, nodeTags)
+		if err != nil {
+			l.Logger.Error("[GetSubscription] count nodes failed: ", logger.Field("error", err.Error()))
+			sub.NodeCount = 0
+		} else {
+			sub.NodeCount = nodeCount
+		}
+		
 		list[i] = sub
 	}
 	resp.List = list