Add shared-root destination state model

internal/config/defaults.go

@@ -47,6 +47,11 @@ const (
 	ReconciliationModeMerge   = "merge"
 )
 
+const (
+	StateModeSingleOwner = "single_owner"
+	StateModeSharedRoot  = "shared_root"
+)
+
 const DefaultS3Region = "us-east-1"
 
 const (
@@ -84,6 +89,9 @@ func ApplyDefaults(cfg *Config) {
 			if destination.Links != nil && destination.Links.Primary == "" {
 				destination.Links.Primary = LinkPrimaryAuto
 			}
+			if destination.State.Mode == "" {
+				destination.State.Mode = StateModeSingleOwner
+			}
 			if destination.Reconciliation.Mode == "" {
 				destination.Reconciliation.Mode = ReconciliationModeReplace
 			}