fix: avoid recursion in lazy imports

[osasisorae]

Summary

• update every autogenerated __getattr__ gateway so that entries mapping to "." import the submodule directly instead of calling back into the parent (prevents the recursion Freezegun triggers)
• add tests/custom/test_lazy_imports.py to reproduce the access pattern and ensure each lazily exported submodule resolves to a real module

Testing

• python -m pip install --break-system-packages aiofiles websockets
• PYTHONPATH=src pytest