fix: restore deviceIndex sentinel value (math.MaxUint32)

The MaxUint32 initialization was intentional as a sentinel value.
Reverting the unnecessary change per review feedback.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: 2 people

packages/orchestrator/pkg/sandbox/nbd/path_direct.go

@@ -78,7 +78,7 @@ func (d *DirectPathMount) Open(ctx context.Context) (retDeviceIndex uint32, err
 
 	telemetry.ReportEvent(ctx, "got backend size")
 
-	var deviceIndex uint32
+	deviceIndex := uint32(math.MaxUint32)
 
 	for {
 		deviceIndex, err = d.devicePool.GetDevice(ctx)