Visualization operators fail due to unquoted enum string values

[xuang7]

What happened?

few visualization operators (ContinuousErrorBands, ContourPlot, Histogram2D) fail at runtime because Java enum methods (e.g., getModeInPlotly, getColoringMethod, getValue) return plain String, which pyb inserts without quotes. This produces invalid Python like mode=lines instead of mode='lines', causing NameError: name 'lines' is not defined.

How to reproduce?

1. Create a workflow: CSVFileScan → ContinuousErrorBands (or ContourPlot, or Histogram2D)
2. Configure the operator with valid columns
3. Run the workflow

Version

1.1.0-incubating (Pre-release/Master)

Commit Hash (Optional)

No response

What browsers are you seeing the problem on?

No response

Relevant log output

[chenlica]

Just curious: was this issue visible before?

[xuang7]

Just curious: was this issue visible before?

This issue appeared after the Python template builder refactor #4189. The new mechanism correctly handles EncodableString, but a few plain String values returned from Java enums were left unchanged, so they are generated without quotes in the Python code, which causes runtime errors.

[chenlica]

Can you add test cases so that this error can be found easily in the future?