Exported Python looks up a column with its exact case where the engine ignores case #9004

What happened?

The engine looks a column up by name ignoring case: Schema lowercases the name in getIndex, containsAttribute and remove, and Tuple.getField goes through it. #7929 brought Projection's drop mode onto the same rule. The exported Python indexes the pandas frame with the name as written, which is case-sensitive. So when an operator's setting names a column in a different case from the table, the workflow runs in Texera and the exported script stops with a KeyError.

This reaches every operator that names a column. On main, Projection (keep and drop) and Filter show it.

How to reproduce?

1. Feed a table with a column name into Projection, and select Name. The engine keeps the column.
2. Export the workflow as Python and run it on the same table. It raises KeyError: "None of [Index(['Name'], dtype='object')] are in the [columns]".
3. Likewise, Filter with the predicate Name = a keeps the matching row in the engine and raises KeyError: 'Name' in the export.

A column picked from the editor's dropdown has the table's exact case, so this shows only for a hand-edited workflow, or after an upstream column changes case.

Version/Branch

1.4.0-incubating-SNAPSHOT (main)

Commit Hash (Optional)

7426431

What browsers are you seeing the problem on?

No response

Relevant log output

KeyError: "None of [Index(['Name'], dtype='object')] are in the [columns]"