The hermes_state split added 15 root-level sibling modules but
[tool.setuptools] py-modules still listed only the old set, so the built
wheel/sdist (and the uv2nix sealed venv) failed at 'import hermes_state'
with ModuleNotFoundError. hermes_state_holders and hermes_state_registry
were already missing on main (registry is imported by gateway/run.py and
hermes_state.py).
Add an invariant test that parses pyproject and walks every import in the
packaged root modules and packages, requiring any import that resolves to
a root-level *.py to be declared - so the class of bug is caught by CI
rather than by a broken install.
eaf10c7e78