Function estimate_conv2d_cost 

pub fn estimate_conv2d_cost(
    batch: u64,
    cin: u64,
    cout: u64,
    oh: u64,
    ow: u64,
    kh: u64,
    kw: u64,
    groups: u64,
) -> OpCost

Estimate cost with explicit numeric dimensions for a Conv2D pattern.