[DEV] Support byte[] in Serializer

From #146:

May be we should extend our Serializer interface to support byte arrays too? As the current implementation will unwrap the ByteBuffer on deserialization.

Start by reading issue #146 and locating the Serializer interface and the current ByteBuffer deserialization path. Clarify the expected byte[] behavior and how it should differ from ByteBuffer handling, then identify the relevant serialization tests or add coverage for the chosen behavior. Done means the interface and implementation consistently preserve byte arrays without unintended unwrapping.

Written by the indexing model from the issue text.