feat(core): dispatch bounded postbox routes

tests/test_organization_hierarchy_contract.py

@@ -6,6 +6,7 @@ from govoplan_core.core.organizations import (
     CAPABILITY_ORGANIZATION_HIERARCHY_DIRECTORY,
     OrganizationDirectory,
     OrganizationFunctionTypeRef,
+    OrganizationHierarchyCatalogRef,
     OrganizationHierarchyDirectory,
     OrganizationUnitTypeRef,
     organization_hierarchy_directory,
@@ -35,6 +36,9 @@ class LegacyOrganizationDirectory:
 
 
 class HierarchyDirectory:
+    def hierarchy_catalog(self, tenant_id):
+        return OrganizationHierarchyCatalogRef(tenant_id=tenant_id)
+
     def get_unit_type(self, _tenant_id, _unit_type_id):
         return None