// Sponza RESOLVE-stage tonemap: Reinhard + gamma 2.2 over the linear
// accumulator — matches the tonemap the megakernel raygen applied inline.
fn resolve_main(coord: vec2<u32>, hdr: vec4<f32>) -> vec4<f32> {
    let mapped = hdr.rgb / (hdr.rgb + vec3<f32>(1.0));
    let g      = pow(mapped, vec3<f32>(1.0 / 2.2));
    return vec4<f32>(g, 1.0);
}