Improve snapshot reliability and usability

__init__.py

@@ -5,9 +5,17 @@ Automatically snapshots workflow state as you edit, with a sidebar panel
 to browse and restore any previous version. Stored in server-side JSON files.
 """
 
-from . import snapshot_routes
-from .snapshot_node import SaveSnapshot
-
 WEB_DIRECTORY = "./js"
-NODE_CLASS_MAPPINGS = {"SaveSnapshot": SaveSnapshot}
-NODE_DISPLAY_NAME_MAPPINGS = {"SaveSnapshot": "Save Snapshot"}
+
+# ComfyUI loads custom nodes as packages. Test runners may import this file as
+# a standalone module while discovering tests; avoid trying to register routes
+# until package-relative imports are available.
+if __package__:
+    from . import snapshot_routes
+    from .snapshot_node import SaveSnapshot
+
+    NODE_CLASS_MAPPINGS = {"SaveSnapshot": SaveSnapshot}
+    NODE_DISPLAY_NAME_MAPPINGS = {"SaveSnapshot": "Save Snapshot"}
+else:
+    NODE_CLASS_MAPPINGS = {}
+    NODE_DISPLAY_NAME_MAPPINGS = {}