fix(python): use uint32 for orig_idx to match SpacePointIndex2

SpacePointIndex2 = std::uint32_t; using int64 caused an implicit
sign/range coercion on every assignSpacePointIndices call.

Author: EliMe5

Examples/Scripts/Python/guntam_transformer_seeder.py

@@ -43,7 +43,7 @@ def _apply_model_acceptance(
     """
     r = np.asarray(sp.r)
     mask = (r < r_max) & (np.abs(xyz[:, 2]) < z_max)
-    return xyz[mask].astype(np.float32), np.where(mask)[0].astype(np.int64)
+    return xyz[mask].astype(np.float32), np.where(mask)[0].astype(np.uint32)
 
 
 def _filter_valid_seeds(