Make marinholab and marinholab.sas namespace packages

[mmmarinho]

marinholab/__init__.py and marinholab/sas/__init__.py made both marinholab and marinholab.sas regular packages. When marinholab-sas-core is installed alongside another distribution that has a marinholab.* package, Python finds the regular package first and hides the other distribution's subpackages:

$ pip install --pre marinholab-sas-core==26.9.13
$ PYTHONPATH=other python -c "import marinholab.other_package"   # other/marinholab/other_package/__init__.py
ModuleNotFoundError: No module named 'marinholab.other_package'

This currently breaks mmmarinho/ur3e_r820: marinholab.ur3e_r820 can't be imported in any environment that has marinholab-sas-core. That includes ghcr.io/marinholab/sas-full:jazzy, whose ROS sas_core package needs marinholab-sas-core. marinholab-solvers-qpoases already leaves its marinholab/ without an __init__.py.

Changes

• Delete marinholab/__init__.py and marinholab/sas/__init__.py. They held only a docstring. Both directories are now PEP 420 namespace packages.
• One package list. [tool.setuptools.packages.find] in pyproject.toml is now the only list, with namespaces = true (the default, now explicit, with a comment explaining why). The explicit packages= list in setup.py is removed; it also left out marinholab.sas.core.modeling.
• CI smoke test: it now imports marinholab.sas.core next to a marinholab.other_package on PYTHONPATH, and asserts that neither marinholab nor marinholab.sas has a __file__.

Testing

• Wheel contents: python -m build --wheel (macOS arm64, Python 3.14) gives the same files as before, minus the two __init__.py.
• New CI check: run locally, it passes on this wheel and fails on the published 26.9.13 with the error above.
• Side by side with other marinholab.* packages: I installed this wheel with marinholab-solvers-qpoases 26.4.0.64 and dqrobotics 26.4.0a7, plus marinholab.ur3e_r820 from source. marinholab.sas.core, marinholab.solvers.qpoases and marinholab.ur3e_r820 import together. curve_revolution_vfi's tests that use SerialManipulatorSimulatorFriendly pass (27), and ur3e_r820's Python tests pass (33).
• Ubuntu: cd docker && docker compose run --rm --build marinholab_sas_core passes all its checks: API, finite-difference Jacobian, examples, no linked dqrobotics shared library, installed files.
• pyright: standard mode reports 0 errors.

🤖 Generated with Claude Code

[mmmarinho]

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