Tests for reference unpacking

The reference packing tests work by upacking and repacking data to ensure it is consistent. However, by mocking the dependencies I think it’s just testing that the mocks pack into the example.

Figure out a way to actually test the unpack procedure.

Locate the existing reference packing tests and the unpack procedure, then read how their dependencies are mocked. Replace the mock-based check with coverage of the actual unpack behavior, and confirm the tests validate real reference data rather than only repacking mock values.

Written by the indexing model from the issue text.