feat: change node ownership to namespace instead of creator

When a node is created in a namespace, the namespace now owns it rather than the creator. This allows namespaces to manage content ownership. Namespace nodes themselves remain owned by their creator. Users retain transitive ownership through their default namespace: user→has_ownership→namespace→has_ownership→node.

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

src/service/node_service_impl.go

@@ -364,8 +364,9 @@ func (s *nodeServiceImpl) Add(input AddInput) (*models.Node, error) {
 			}
 		}
 
-		// Edge rels.
+		// Edge rels. Track the namespace the node is placed in for ownership.
 		hasCreated := false
+		var actualNsID string
 		for _, ri := range input.Rels {
 			if ri.Target == "" {
 				continue // already stored as tag
@@ -377,6 +378,9 @@ func (s *nodeServiceImpl) Add(input AddInput) (*models.Node, error) {
 			if err != nil {
 				return err
 			}
+			if ri.Type == models.RelInNamespace {
+				actualNsID = resolved
+			}
 			if ri.Type == models.RelHasOwnership {
 				// Ownership transfer: remove existing owner of the target.
 				existingOwners, _ := st.FindNodes([]*models.Rel{{Type: models.RelHasOwnership, Target: resolved}})
@@ -398,6 +402,7 @@ func (s *nodeServiceImpl) Add(input AddInput) (*models.Node, error) {
 			if err := st.AddRel(id, string(models.RelInNamespace), nsID); err != nil {
 				return err
 			}
+			actualNsID = nsID
 		}
 
 		// Default created.
@@ -411,12 +416,19 @@ func (s *nodeServiceImpl) Add(input AddInput) (*models.Node, error) {
 			}
 		}
 
-		// Grant creator ownership of the new node.
+		// Grant ownership of the new node.
+		// Namespace nodes are owned by their creator. All other nodes are owned
+		// by the namespace they belong to — the user retains transitive ownership
+		// through the namespace's own ownership chain (e.g. user→owns→default-ns→owns→node).
 		creatorID, err := s.resolveUserRef(st, s.userID)
 		if err != nil {
 			return err
 		}
-		if err := st.AddRel(creatorID, string(models.RelHasOwnership), id); err != nil {
+		ownerID := creatorID
+		if tmp.GetProperty("type") != "namespace" && actualNsID != "" {
+			ownerID = actualNsID
+		}
+		if err := st.AddRel(ownerID, string(models.RelHasOwnership), id); err != nil {
 			return err
 		}