Function append_native_observation_quins 

pub fn append_native_observation_quins(
    storage_root: &Path,
    media_hash: u64,
    media_byte_len: u64,
    model_hash: u64,
    detections: &[NativeDetection],
) -> Result<usize, VisionError>

Append native observation quins to vision_native.wal (no active VLM required).