Function decode_centroid_entry 

pub fn decode_centroid_entry(
    buf: &mut &[u8],
    dimensions: usize,
) -> Result<CentroidEntry, EncodingError>

Decode a centroid entry with known dimensionality.

Note: This is a standalone function rather than a Decode trait impl because decoding requires the dimensions parameter from CollectionMeta. The Decode trait signature doesn’t allow passing external context.