feat: expose organization hierarchy catalog

tests/test_hierarchy_directory.py

@@ -240,6 +240,29 @@ class OrganizationHierarchyDirectoryTests(unittest.TestCase):
             project.matches[0].path[0].relation_type.id,
         )
 
+    def test_hierarchy_catalog_is_tenant_scoped_and_preserves_structure_links(
+        self,
+    ) -> None:
+        catalog = self.directory.hierarchy_catalog("tenant-1")
+        empty = self.directory.hierarchy_catalog("tenant-2")
+
+        self.assertEqual(
+            {self.employer.id, self.project.id},
+            {item.id for item in catalog.structures},
+        )
+        self.assertEqual(
+            {
+                (self.employer_parent.id, self.employer.id),
+                (self.project_parent.id, self.project.id),
+            },
+            {
+                (item.id, item.structure_id)
+                for item in catalog.relation_types
+            },
+        )
+        self.assertEqual((), empty.structures)
+        self.assertEqual((), empty.relation_types)
+
     def test_bounded_paths_report_depth_and_cycles(self) -> None:
         bounded = self.directory.resolve_hierarchy_relatives(
             "tenant-1",