Function parse_supervised_dataset_csv 

pub fn parse_supervised_dataset_csv(
    content: &str,
    config: &SupervisedCsvConfig,
) -> Result<SupervisedDataset, ModelError>

Parses supervised training samples from CSV text into a SupervisedDataset.

Each non-empty line is treated as one sample row with input_len + target_len numeric columns. Optional header row skipping is controlled by config.has_header.