feat(ops): 添加分组和账号级别监控指标

- 后端新增 GetAccountAvailability 方法获取账号可用性数据
- 添加分组可用率和限流率计算辅助函数
- 前端支持分组和账号级别的监控指标类型
- 优化警报规则指标选择器,按类别分组显示

backend/internal/service/ops_account_availability.go

@@ -2,6 +2,7 @@ package service
 
 import (
 	"context"
+	"errors"
 	"time"
 )
 
@@ -155,3 +156,39 @@ func (s *OpsService) GetAccountAvailabilityStats(ctx context.Context, platformFi
 
 	return platform, group, account, &collectedAt, nil
 }
+
+type OpsAccountAvailability struct {
+	Group       *GroupAvailability
+	Accounts    map[int64]*AccountAvailability
+	CollectedAt *time.Time
+}
+
+func (s *OpsService) GetAccountAvailability(ctx context.Context, platformFilter string, groupIDFilter *int64) (*OpsAccountAvailability, error) {
+	if s == nil {
+		return nil, errors.New("ops service is nil")
+	}
+
+	if s.getAccountAvailability != nil {
+		return s.getAccountAvailability(ctx, platformFilter, groupIDFilter)
+	}
+
+	_, groupStats, accountStats, collectedAt, err := s.GetAccountAvailabilityStats(ctx, platformFilter, groupIDFilter)
+	if err != nil {
+		return nil, err
+	}
+
+	var group *GroupAvailability
+	if groupIDFilter != nil && *groupIDFilter > 0 {
+		group = groupStats[*groupIDFilter]
+	}
+
+	if accountStats == nil {
+		accountStats = map[int64]*AccountAvailability{}
+	}
+
+	return &OpsAccountAvailability{
+		Group:       group,
+		Accounts:    accountStats,
+		CollectedAt: collectedAt,
+	}, nil
+}