feat(ops): 新增实时流量数据层

- 添加实时流量repository层实现
- 添加实时流量service层逻辑
- 定义实时流量数据模型

backend/internal/service/ops_realtime_traffic_models.go

@@ -0,0 +1,19 @@
+package service
+
+import "time"
+
+// OpsRealtimeTrafficSummary is a lightweight summary used by the Ops dashboard "Realtime Traffic" card.
+// It reports QPS/TPS current/peak/avg for the requested time window.
+type OpsRealtimeTrafficSummary struct {
+	// Window is a normalized label (e.g. "1min", "5min", "30min", "1h").
+	Window string `json:"window"`
+
+	StartTime time.Time `json:"start_time"`
+	EndTime   time.Time `json:"end_time"`
+
+	Platform string `json:"platform"`
+	GroupID  *int64 `json:"group_id"`
+
+	QPS OpsRateSummary `json:"qps"`
+	TPS OpsRateSummary `json:"tps"`
+}