Function mean_pool 

pub fn mean_pool(
    output_data: &[f32],
    seq_len: usize,
    hidden_dim: usize,
    attention_mask: &[i64],
    output_dim: usize,
) -> Vec<f32>

Mean pooling over sequence dimension with attention mask

Ported from examples/embeddings.rs create_embedding() function. Averages token embeddings, respecting attention mask.

Arguments

• output_data - Flattened ONNX output tensor
• seq_len - Sequence length
• hidden_dim - Hidden dimension size
• attention_mask - Mask indicating real vs padded tokens (1 = real, 0 = padding)
• output_dim - Target embedding dimension

Returns

• Pooled embedding vector (averaged over real tokens only)