refactor: modularize audit and harden build validation

audit/internal/webui/task_runner.go

@@ -224,7 +224,10 @@ func executeTaskWithOptions(opts *HandlerOptions, t *Task, j *jobState, ctx cont
 			err = fmt.Errorf("app not configured")
 			break
 		}
-		archive, err = a.RunNvidiaBandwidthPack(ctx, "", t.params.GPUIndices, j.append)
+		// Validate: one nvbandwidth pass over all selected GPUs. Stress
+		// (deep): per-socket passes then an all-GPU pass, so a cross-socket
+		// P2P fault is isolated from a same-socket one.
+		archive, err = a.RunNvidiaBandwidthPack(ctx, "", t.params.GPUIndices, t.params.StressMode, j.append)
 	case "nvidia-interconnect":
 		if a == nil {
 			err = fmt.Errorf("app not configured")