Fix EnumSerializer.write to accept numpy scalars from NDArray of records

[SAY-5]

Closes #284.

EnumSerializer.write assumed its value argument was always a Python Enum, but when called from RecordSerializer._write on the numpy write path (where a record is iterated as value['fieldname'] from a np.void scalar), it receives a bare np.integer and crashes with AttributeError: 'numpy.uint64' object has no attribute 'value'. This affected any T[] whose element type was a record containing one or more enum fields.

Fix unwraps .value only when value is an Enum; numpy scalars (which _integer_serializer.write already accepts) are passed through. Adds python/tests/test_enum_in_ndarray.py covering: the original NDArray-of-record-with-enums reproducer, the bare numpy-scalar path directly through EnumSerializer.write, and the existing Python-Enum path (to guard against regression).

[naegelejd]

This is not the right way to test this.

The test model should be updated such that it reproduces the issue. Then regression tests can be added to test_generated_types.py and test_protocol_roundtrip.py. Then, an equivalent test should be added for C++ and MATLAB to ensure no similar bugs exist.

[SAY-5]

Understood, that's a much bigger refactor than I have bandwidth for; happy to close in favour of a more thorough fix.

[SAY-5]

Understood, the proper test should reproduce the bug through the YAML test model and have regression coverage in the generated-types and protocol-roundtrip suites for Python, C++, and MATLAB. That's a substantially different scope from this PR, so I'll close this and open a follow-up once the test model and codegen changes are ready.

[SAY-5]

Closing per maintainer feedback, will resubmit with the proper test model approach.

[SAY-5]

Reopened. Reworking per your feedback: I'll update the test model to reproduce the issue, add regression tests in test_generated_types.py and test_protocol_roundtrip.py, and add equivalent coverage for C++ and MATLAB to confirm no similar bugs exist there. Will push and re-ping.