Bitswap's internal data structures (client wantlists, block store) now fully utilize ``py-cid`` objects (``CIDObject``) instead of raw ``bytes`` as keys. Public APIs continue to accept ``CIDInput`` transparently. The legacy ``cid_to_string`` and ``parse_cid_version`` helpers have been removed in favor of the new ``parse_cid`` and ``cid_to_text`` functions, and the ``__init__.py`` exports have been organized into preferred and backward-compatible tiers. **Breaking change:** external code that imports ``cid_to_string`` or ``parse_cid_version`` must migrate to ``cid_to_text`` and ``parse_cid(cid).version``, respectively.