fix: omit unfetchable list blobs from column discovery

docs/src/js/classes/Table.md

@@ -143,7 +143,8 @@ containing the new version number of the table after altering the columns.
 abstract blobColumns(): Promise<string[]>
 ```
 
-Blob v2 columns, including nested dotted paths.
+Blob v2 columns addressable by row ID, including struct-nested dotted paths.
+Blobs inside lists are omitted because a row ID does not identify an element.
 
 #### Returns
 
@@ -548,6 +549,7 @@ Bytes for `column` at row IDs from [Query.withRowId](Query.md#withrowid).
 Reads the table's current checkout. IDs from another version can fail after
 compaction unless stable row ids are enabled. Results keep input order and
 duplicates. Null blobs are `null`. Empty blobs are empty buffers.
+Blobs inside lists cannot be fetched by row ID.
 
 #### Parameters
 

docs/src/js/functions/blob.md

@@ -14,6 +14,8 @@ Declares a `lance.blob.v2` column.
 
 Query results are descriptors, not payload bytes. Use [Table.fetchBlobs](../classes/Table.md#fetchblobs)
 or [Table.fetchBlobFiles](../classes/Table.md#fetchblobfiles) to read bytes.
+Blobs inside lists can be written and queried as descriptors, but cannot
+currently be fetched because a row ID does not identify a list element.
 
 ## Parameters
 

docs/src/python/python.md

@@ -323,6 +323,10 @@ still work. Queries return descriptors. Call
 [`fetch_blob_files`][lancedb.table.Table.fetch_blob_files] for lazy reads or
 [`fetch_blobs`][lancedb.table.Table.fetch_blobs] for eager bytes.
 
+Blobs inside lists can be written and queried as descriptors. They are omitted
+from `blob_columns()` because row ids do not identify individual list elements,
+so the fetch APIs cannot read their bytes yet.
+
 ::: lancedb.blob
 
 ::: lancedb._blob.BlobFile