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/repository/ops_repo_realtime_traffic.go

+package repository
+
+import (
+	"context"
+	"fmt"
+	"strings"
+	"time"
+
+	"github.com/Wei-Shaw/sub2api/internal/service"
+)
+
+func (r *opsRepository) GetRealtimeTrafficSummary(ctx context.Context, filter *service.OpsDashboardFilter) (*service.OpsRealtimeTrafficSummary, error) {
+	if r == nil || r.db == nil {
+		return nil, fmt.Errorf("nil ops repository")
+	}
+	if filter == nil {
+		return nil, fmt.Errorf("nil filter")
+	}
+	if filter.StartTime.IsZero() || filter.EndTime.IsZero() {
+		return nil, fmt.Errorf("start_time/end_time required")
+	}
+
+	start := filter.StartTime.UTC()
+	end := filter.EndTime.UTC()
+	if start.After(end) {
+		return nil, fmt.Errorf("start_time must be <= end_time")
+	}
+
+	window := end.Sub(start)
+	if window <= 0 {
+		return nil, fmt.Errorf("invalid time window")
+	}
+	if window > time.Hour {
+		return nil, fmt.Errorf("window too large")
+	}
+
+	usageJoin, usageWhere, usageArgs, next := buildUsageWhere(filter, start, end, 1)
+	errorWhere, errorArgs, _ := buildErrorWhere(filter, start, end, next)
+
+	q := `
+WITH usage_buckets AS (
+  SELECT
+    date_trunc('minute', ul.created_at) AS bucket,
+    COALESCE(COUNT(*), 0) AS success_count,
+    COALESCE(SUM(input_tokens + output_tokens + cache_creation_tokens + cache_read_tokens), 0) AS token_sum
+  FROM usage_logs ul
+  ` + usageJoin + `
+  ` + usageWhere + `
+  GROUP BY 1
+),
+error_buckets AS (
+  SELECT
+    date_trunc('minute', created_at) AS bucket,
+    COALESCE(COUNT(*), 0) AS error_count
+  FROM ops_error_logs
+  ` + errorWhere + `
+    AND COALESCE(status_code, 0) >= 400
+  GROUP BY 1
+),
+combined AS (
+  SELECT
+    COALESCE(u.bucket, e.bucket) AS bucket,
+    COALESCE(u.success_count, 0) AS success_count,
+    COALESCE(u.token_sum, 0) AS token_sum,
+    COALESCE(e.error_count, 0) AS error_count,
+    COALESCE(u.success_count, 0) + COALESCE(e.error_count, 0) AS request_total
+  FROM usage_buckets u
+  FULL OUTER JOIN error_buckets e ON u.bucket = e.bucket
+)
+SELECT
+  COALESCE(SUM(success_count), 0) AS success_total,
+  COALESCE(SUM(error_count), 0) AS error_total,
+  COALESCE(SUM(token_sum), 0) AS token_total,
+  COALESCE(MAX(request_total), 0) AS peak_requests_per_min,
+  COALESCE(MAX(token_sum), 0) AS peak_tokens_per_min
+FROM combined`
+
+	args := append(usageArgs, errorArgs...)
+	var successCount int64
+	var errorTotal int64
+	var tokenConsumed int64
+	var peakRequestsPerMin int64
+	var peakTokensPerMin int64
+	if err := r.db.QueryRowContext(ctx, q, args...).Scan(
+		&successCount,
+		&errorTotal,
+		&tokenConsumed,
+		&peakRequestsPerMin,
+		&peakTokensPerMin,
+	); err != nil {
+		return nil, err
+	}
+
+	windowSeconds := window.Seconds()
+	if windowSeconds <= 0 {
+		windowSeconds = 1
+	}
+
+	requestCountTotal := successCount + errorTotal
+	qpsAvg := roundTo1DP(float64(requestCountTotal) / windowSeconds)
+	tpsAvg := roundTo1DP(float64(tokenConsumed) / windowSeconds)
+
+	// Keep "current" consistent with the dashboard overview semantics: last 1 minute.
+	// This remains "within the selected window" since end=start+window.
+	qpsCurrent, tpsCurrent, err := r.queryCurrentRates(ctx, filter, end)
+	if err != nil {
+		return nil, err
+	}
+
+	qpsPeak := roundTo1DP(float64(peakRequestsPerMin) / 60.0)
+	tpsPeak := roundTo1DP(float64(peakTokensPerMin) / 60.0)
+
+	return &service.OpsRealtimeTrafficSummary{
+		StartTime: start,
+		EndTime:   end,
+		Platform:  strings.TrimSpace(filter.Platform),
+		GroupID:   filter.GroupID,
+		QPS: service.OpsRateSummary{
+			Current: qpsCurrent,
+			Peak:    qpsPeak,
+			Avg:     qpsAvg,
+		},
+		TPS: service.OpsRateSummary{
+			Current: tpsCurrent,
+			Peak:    tpsPeak,
+			Avg:     tpsAvg,
+		},
+	}, nil
+}

backend/internal/service/ops_realtime_traffic.go

+package service
+
+import (
+	"context"
+	"time"
+
+	infraerrors "github.com/Wei-Shaw/sub2api/internal/pkg/errors"
+)
+
+// GetRealtimeTrafficSummary returns QPS/TPS current/peak/avg for the provided window.
+// This is used by the Ops dashboard "Realtime Traffic" card and is intentionally lightweight.
+func (s *OpsService) GetRealtimeTrafficSummary(ctx context.Context, filter *OpsDashboardFilter) (*OpsRealtimeTrafficSummary, error) {
+	if err := s.RequireMonitoringEnabled(ctx); err != nil {
+		return nil, err
+	}
+	if s.opsRepo == nil {
+		return nil, infraerrors.ServiceUnavailable("OPS_REPO_UNAVAILABLE", "Ops repository not available")
+	}
+	if filter == nil {
+		return nil, infraerrors.BadRequest("OPS_FILTER_REQUIRED", "filter is required")
+	}
+	if filter.StartTime.IsZero() || filter.EndTime.IsZero() {
+		return nil, infraerrors.BadRequest("OPS_TIME_RANGE_REQUIRED", "start_time/end_time are required")
+	}
+	if filter.StartTime.After(filter.EndTime) {
+		return nil, infraerrors.BadRequest("OPS_TIME_RANGE_INVALID", "start_time must be <= end_time")
+	}
+	if filter.EndTime.Sub(filter.StartTime) > time.Hour {
+		return nil, infraerrors.BadRequest("OPS_TIME_RANGE_TOO_LARGE", "invalid time range: max window is 1 hour")
+	}
+
+	// Realtime traffic summary always uses raw logs (minute granularity peaks).
+	filter.QueryMode = OpsQueryModeRaw
+
+	return s.opsRepo.GetRealtimeTrafficSummary(ctx, filter)
+}

backend/internal/service/ops_realtime_traffic_models.go

+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"`
+}