fix(pcie): verify GPU links under real bandwidth load

audit/internal/platform/sat_gpu_packs.go

@@ -451,6 +451,10 @@ func (s *System) RunNvidiaBandwidthPack(ctx context.Context, baseDir string, gpu
 		return "", err
 	}
 	killStaleNvidiaTestWorkers(logFunc)
+	linkFindings, err := captureNvidiaPCIeLinkBaseline(selected)
+	if err != nil {
+		return "", err
+	}
 	jobs := []satJob{
 		{name: "01-nvidia-smi-q.log", cmd: []string{"nvidia-smi", "-q"}},
 		{name: "02-dcgmi-discovery.log", cmd: []string{"dcgmi", "discovery", "-l"}, informational: true, retries: 2},
@@ -476,6 +480,7 @@ func (s *System) RunNvidiaBandwidthPack(ctx context.Context, baseDir string, gpu
 			collectGPU:  true,
 			gpuIndices:  selected,
 			syncBracket: true,
+			afterRun:    func() { sampleNvidiaPCIeLinkAfterLoad(linkFindings) },
 		})
 		step++
 	} else {
@@ -495,15 +500,17 @@ func (s *System) RunNvidiaBandwidthPack(ctx context.Context, baseDir string, gpu
 			collectGPU:  true,
 			gpuIndices:  selected,
 			syncBracket: true,
+			afterRun:    func() { sampleNvidiaPCIeLinkAfterLoad(linkFindings) },
 		})
-		step++
 	}
-	jobs = append(jobs, satJob{
-		name: fmt.Sprintf("%02d-nvidia-smi-after.log", step),
-		cmd:  []string{"nvidia-smi", "--query-gpu=index,name,temperature.gpu,power.draw,utilization.gpu,memory.used,memory.total", "--format=csv,noheader,nounits"},
-	})
-
-	return runAcceptancePackCtx(ctx, baseDir, "gpu-nvidia-bandwidth", withNvidiaPersistenceMode(jobs...), logFunc)
+	runDir, err := runAcceptancePackCtx(ctx, baseDir, "gpu-nvidia-bandwidth", withNvidiaPersistenceMode(jobs...), logFunc)
+	if err != nil {
+		return "", err
+	}
+	if err := finishNvidiaPCIeLinkCheck(runDir, linkFindings); err != nil {
+		return "", err
+	}
+	return runDir, nil
 }
 
 func (s *System) RunNvidiaAcceptancePack(baseDir string, logFunc func(string)) (string, error) {