Function deserialize 

pub fn deserialize<'de, D: Deserializer<'de>>(
    deserializer: D,
) -> Result<Pooling, D::Error>

Deserialize accepts both shapes regardless of the deserializer’s human-readable flag — mirrors the BinaryData / Identifier pattern. Necessary because platform_value::to_value reports HR=false (emits the numeric discriminant on the way to JsValue), but platform_value::from_value reports HR=true on the way back. Without dual acceptance, the fromObject(toObject()) round-trip fails on the pooling field.