feat(volume): add IsRemount to MounterArgs

Thread the reconciler's existing isRemount signal into MounterArgs so
volume plugins can distinguish an initial publish from a republish
(e.g. CSIDriver.spec.requiresRepublish=true). No behavior change.

pkg/volume/util/operationexecutor/operation_generator.go

@@ -586,6 +586,7 @@ func (og *operationGenerator) GenerateMountVolumeFunc(
 			FSGroupChangePolicy: fsGroupChangePolicy,
 			Recorder:            og.recorder,
 			SELinuxLabel:        volumeToMount.SELinuxLabel,
+			IsRemount:           isRemount,
 		})
 		// Update actual state of world
 		markOpts := MarkVolumeOpts{

pkg/volume/volume.go

@@ -138,6 +138,16 @@ type MounterArgs struct {
 	// Optional interface that will be used to change the ownership of the volume, if specified.
 	// mainly used by unit tests
 	VolumeOwnershipApplicator VolumeOwnershipChanger
+
+	// IsRemount is true when SetUp is being invoked on a volume that the
+	// reconciler considers already mounted to the pod, e.g. a periodic
+	// republish triggered by CSIDriver.spec.requiresRepublish=true. Volume
+	// plugins should use this to avoid destroying state (e.g. mount
+	// directories, volume metadata files) that the pod is currently
+	// observing through an existing bind mount, since teardown on a
+	// failed remount cannot be repaired by a subsequent successful
+	// remount and would leave the pod with stale contents.
+	IsRemount bool
 }
 
 type VolumeOwnershipChanger interface {