Function build_simple_cnn_classifier 

pub fn build_simple_cnn_classifier(
    model: &mut SequentialModel,
    graph: &mut Graph,
    input_channels: usize,
    num_classes: usize,
    stage_channels: &[usize],
    epsilon: f32,
) -> Result<(), ModelError>

Builds a simple CNN classifier architecture for NHWC input.

Architecture: [Conv->BN->ReLU->MaxPool] x stages -> GlobalAvgPool -> Flatten -> Linear. This is a convenient builder for common CV classification tasks.