👌 ShellCode: drop redundant Model override

[GeigerJ2]

commit msg:

aiida-core PR 6990 restructured the pydantic model layout on `Code`
classes: the single nested `Model` class is split into `CommonFields`,
`AttributesModel`, and `ConstructorArgsModel`. `ShellCode` overrides
these to set `default_calc_job_plugin = 'core.shell'` for attribute
loading and the `verdi code create` CLI default.

PR 6990 is not in any released `aiida-core` yet (as of 2026-05-20), so
keep both code paths: feature-detect the new API via the presence of
`aiida.orm.pydantic.OrmMetadataField` (added in 6990) and fall back to
the old single-class `Model` shape on releases that predate the
refactor. The dependency pin stays at `aiida-core~=2.6,>=2.6.1`.

[edan-bainglass]

Thanks @GeigerJ2, but actually, I think maybe we just remove the model entirely from aiida-shell? It adds nothing new, right? default_calc_job_plugin is already available in the root AbstractCode model.

[GeigerJ2]

Thanks @GeigerJ2, but actually, I think maybe we just remove the model entirely from aiida-shell? It adds nothing new, right? default_calc_job_plugin is already available in the root AbstractCode model.

He, good catch! You're right, I pushed a follow-up that drops the Model override entirely instead of feature-detecting both APIs.

I walked through the construction paths in both old and new aiida-core to convince myself nothing breaks:

• default_calc_job_plugin is declared on AbstractCode (old: Model, new: CommonFields) with default None.
• cls.from_model(model) → _from_cli_model(model) (new) or _from_model(model) (old) → fields = model._to_orm_field_values() → cls(**fields).
• Both old (model_to_orm_field_values, entities.py) and new (_to_orm_field_values, pydantic.py) filter out None values with the same if field_value is None: continue line. So default_calc_job_plugin=None never reaches the constructor.
• ShellCode.__init__ still has default_calc_job_plugin: str = 'core.shell' in its signature, so when the field is filtered out, the right value is applied. validate_default_calc_job_plugin is still enforced for any explicitly-passed non-core.shell value.

I confirmed against an installed venv: verdi code create core.code.installed.shell --help shows -P, --default-calc-job-plugin TEXT with no printed default, which is the only observable change. The actual constructed code still has default_calc_job_plugin='core.shell' set correctly because the __init__ default takes over once None is filtered out.

[edan-bainglass]

Thanks. LGTM!