memory (sqla): Add with_parent and with_link to get_pubsub_nodes():

Added `with_parent` and `with_link` parameters for eager loading of parent and linked_node
relationships.

Fixed CTE to include all children (not just base nodes) and use `selectinload` for parent
to avoid cartesian products.

rel 476

libervia/backend/memory/sqla.py

@@ -1283,6 +1283,8 @@ class Storage:
         with_items: bool = False,
         with_subscriptions: bool = False,
         with_affiliations: bool = False,
+        with_parent: bool = False,
+        with_link: bool = False,
     ) -> list[PubsubNode]:
         """Retrieve pubsub nodes with their hierarchy and linking nodes.
 
@@ -1300,6 +1302,8 @@ class Storage:
         @param with_items: If True, eagerly load items for each node.
         @param with_subscriptions: If True, eagerly load subscriptions for each node.
         @param with_affiliations: If True, eagerly load affiliations for each node.
+        @param with_parent: If True, eagerly load parent_node for each node.
+        @param with_link: If True, eagerly load linked_node for each node.
         @return: List of base nodes matching criteria (root nodes of the request).
         """
         # Base criteria that always apply
@@ -1313,13 +1317,15 @@ class Storage:
         criteria.append(PubsubNode.linked_node_id.is_(None))
 
         # Prepare query options
+        # Always include parent_node and linked_node for all nodes when requested
+        options = []
         if depth > 0:
-            options = [
-                selectinload(PubsubNode.child_nodes),
-                joinedload(PubsubNode.parent_node),
-            ]
-        else:
-            options = []
+            # Load child_nodes when depth > 0 so hierarchy can be traversed
+            options.append(selectinload(PubsubNode.child_nodes))
+        if with_parent:
+            options.append(selectinload(PubsubNode.parent_node))
+        if with_link:
+            options.append(joinedload(PubsubNode.linked_node))
         if with_items:
             options.append(selectinload(PubsubNode.items))
         if linked_node:
@@ -1369,13 +1375,11 @@ class Storage:
                     .cte(name="hierarchy", recursive=True)
                 )
 
-                # Recursive part: get direct children that are also base nodes.
+                # Recursive part: get direct children (including nodes with linked_node_id).
                 children = (
                     select(PubsubNode.id, hierarchy.c.depth + 1)
                     .join(hierarchy, PubsubNode.parent_node_id == hierarchy.c.id)
-                    .filter(
-                        hierarchy.c.depth < depth, PubsubNode.linked_node_id.is_(None)
-                    )
+                    .filter(hierarchy.c.depth < depth)
                 )
 
                 # Combine and create the full hierarchy.