swev-id: sphinx-doc__sphinx-8459 - honor autodoc type aliases

[casey-brooks]

Summary

• apply autodoc_type_aliases when recording description-based type hints
• add regression coverage that builds a project with autodoc_typehints='description' and asserts alias names reach the rendered Parameters/Return sections

Reproduction

1. Checkout sphinx-doc__sphinx-8459 and create a virtualenv.
2. pip install -e '.[test]' followed by the branch pins (pip install 'Jinja2<3.1' 'MarkupSafe<2.1' 'docutils>=0.16,<0.17' roman 'alabaster==0.7.12' 'Pygments==2.17.2' 'sphinxcontrib-applehelp==1.0.4' 'sphinxcontrib-devhelp==1.0.2' 'sphinxcontrib-htmlhelp==1.0.3' 'sphinxcontrib-qthelp==1.0.3' 'sphinxcontrib-serializinghtml==1.1.4').
3. PYTHONPATH=$(pwd) pytest tests/test_ext_autodoc_configs.py::test_autodoc_typehints_description_respects_aliases -q

Observed Failure

E       AssertionError: assert 'Parameters:\n      **value** (*AliasName*) --' in 'aliaspkg.alias_description.use_alias(value)\n\n   Return the provided value unchanged.\n\n   Parameters:\n      **value** (*aliaspkg.alias_description.AliasTarget*) --\n\n   Return type:\n      aliaspkg.alias_description.AliasTarget\n'

Testing

• flake8 tests/test_ext_autodoc_configs.py sphinx/ext/autodoc/typehints.py
• PYTHONPATH=$(pwd) pytest tests/test_ext_autodoc_configs.py::test_autodoc_typehints_description -q
• PYTHONPATH=$(pwd) pytest tests/test_ext_autodoc_configs.py::test_autodoc_typehints_description_respects_aliases -q

[noa-lucent]

Looks great. Applying autodoc_type_aliases inside record_typehints keeps the description-mode annotations aligned with the rest of autodoc, and the new regression test exercises alias rendering end-to-end. Thanks for adding coverage.