Enable creating graph from datastore YAML file

[matschreiner]

This PR adds support for creating graphs directly from datastores. The current approach introduces unnecessary complexity by requiring neural_lam_config, even though graph creation only needs a datastore, and the sole function of the neural_lam_config in this context is to be the owner of the datastore path.

The first positional argument in

python -m neural_lam.create_graph first_arg

still refers to a neurallam_config and if both datastore and neurallam_config are specified, neurallam_config takes precedence, ensuring this is a non-breaking change. However, I propose deprecating neurallam_config usage in the future.

Imports are now explicit instead of relative, allowing create_graph.py to be executed both as a standalone script (python create_graph.py) and as a module (python -m neural_lam.create_graph).
This change improves usability, as some users feel more confident running scripts the traditional way.

New Script Arguments:

--datastore: Path to the datastore.
--datastore_type: Type of datastore (defaults to mdp). The script will throw an error if an invalid type is provided.

The change doesn't introduce any new dependencies to the code.

• 🐛 Bug fix (non-breaking change that fixes an issue)
• ✨ New feature (non-breaking change that adds functionality)
• 💥 Breaking change (fix or feature that would cause existing functionality to not work as expected)
• 📖 Documentation (Addition or improvements to documentation)

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[matschreiner]

@leifdenby

[joeloskarsson]

As we are working towards #83, I am not sure how to prioritize updates to the current create_graph.py. But this is a small and useful change, however the PR would need to be made up to date with main. If you wan to do this we can go ahead and push this through, but if you feel that this is not worth putting effort to now we should probably just close this or change to a draft PR. Tagging also @leifdenby for visibility.

[sadamov]

Thanks @matschreiner. Following up on @joeloskarsson's earlier suggestion - closing this in favour of the weather-model-graphs migration in #384 / #596, since create_graph.py won't see further development. Reopen if you'd like to revive against the new path once it lands.