fix: simulators call af.ex.util, and the chain-run resolves in a notebook (PENDING RELEASE)

[Jammy2211]

Workspace half of PyAutoLabs/PyAutoFit#1444. PENDING RELEASE — needs the af.ex.util helpers from PyAutoLabs/PyAutoFit#1445 to ship first.

Two failures in the same notebook, the second masked by the first.

1. ModuleNotFoundError: No module named 'util'

notebooks/simulators/simulators.ipynb and simulators_sample.ipynb failed workspace smoke (PyAutoHeart run 30790463134).

scripts/simulators/util.py could only ever be imported by the .py scripts: running one puts scripts/simulators/ on sys.path[0]. A notebook kernel has no script directory — sys.path[0] is the cwd — so the generated notebooks could never import it. Not a cwd bug: import util fails from the notebook's own directory and from the workspace root.

The four simulate helpers now live in af.ex.util, so the same call works from a script, a notebook and Colab alike. scripts/simulators/util.py is deleted along with the util.ipynb it generated.

2. The chain-run cell, found while fixing the first

scripts/simulators/simulators.py ends by chain-running simulators_sample.py so every tutorial's simulator subprocess also produces the chapter-3 sample folders. It resolved that path from the script's own file path — which a notebook kernel does not define, and which points into the notebooks tree where no .py exists in any case.

That cell survives into notebooks/simulators/simulators.ipynb, so it would have failed the instant the import above was fixed — it was simply never reached before. The path is now relative to the repository root, which the script run, the pinned notebook kernel and Colab all share.

Verification

• Both simulator notebooks execute clean via the same runner smoke uses — including the chain-run cell, confirmed by the chapter-3 sample dataset folders it produces.
• Both .py siblings pass.
• run_smoke.py: 10/10 passed.
• check_navigator.py --banners=fail: OK.
• Notebooks regenerated with generate.py howtofit (15 scripts); the diff touches only the simulator files plus llms-full.txt / workspace_index.json.

🤖 Generated with Claude Code