Update verified WDS index (6513 shards)

README.md

@@ -12,6 +12,12 @@ repositories are parts of the same release; consult each `manifest.json`.
 The manifest lists **only uploaded shards whose remote size and SHA-256 have
 been verified**. An incomplete manifest is not a complete dataset.
 
+New uploads use bucketed paths such as
+`wds_v20260913/UCO3D_shards/uco3d-train/00017/uco3d-train-017395.tar`.
+Each leaf holds at most 1,000 tar/JSON pairs. Already uploaded legacy paths
+remain unchanged. Use the explicit paths or pinned URLs in the manifests;
+do not assume every shard sits in a single dataset directory.
+
 ## Scope and splits
 
 All 23 sources in the current SpatialEncoder training catalog are in scope.