Allow model providers to restrict workflows to approved models

[eric-tramel]

Priority Level

Medium (Nice to have)

Is your feature request related to a problem? Please describe.

Model providers can expose many models, but a DataDesigner user or organization may only want workflows to use a smaller approved subset. For example, a provider entry may point at OpenRouter, while the user wants that provider to be valid only for open-source models, internal-approved models, or another policy-driven subset.

Today there is no user-facing way to express that provider-level approval boundary and have workflow ModelConfig entries checked against it before generation runs. This makes it easy for a workflow config to accidentally reference a model that is available through the provider but not approved for the user's intended usage policy.

Describe the solution you'd like

DataDesigner should support an optional approved-model list on a model provider configuration. When a provider has an approved-model list, workflow configs should be considered valid only when every ModelConfig using that provider references a model on the provider's approved list.

Expected user behavior:

• A user can configure a provider with no approved-model list, preserving the current behavior where any provider-supported model name may be used.
• A user can configure a provider with an approved-model list, such as a curated set of open-source OpenRouter models.
• When validating or running a workflow config, DataDesigner checks each ModelConfig against the approved list for its provider.
• If a workflow references a non-approved model for that provider, DataDesigner reports a clear validation error naming the provider, the rejected model, and the configured approval boundary.
• The provider configuration TUI exposes this as an optional setting, so users who do not need provider-level restrictions can skip it.
• The TUI should make it clear when a provider is unrestricted versus restricted to an approved list.

Small usage example:

providers:
  openrouter-oss:
    provider: openrouter
    approved_models:
      - meta-llama/llama-3.3-70b-instruct
      - mistralai/mixtral-8x7b-instruct

models:
  - alias: record_writer
    provider: openrouter-oss
    model: meta-llama/llama-3.3-70b-instruct

In this example, record_writer is valid because it uses a model approved for openrouter-oss. If the workflow changed that same model config to model: anthropic/claude-sonnet-4, DataDesigner should reject the workflow before generation because that model is outside the provider's approved list.

Describe alternatives you've considered

• Relying on users to manually audit workflow configs before running them.
• Encoding approval policy outside DataDesigner, such as in separate documentation or wrapper scripts.
• Creating separate provider entries by convention without DataDesigner understanding that the provider is intended to be restricted.

Agent Investigation

Reviewed existing GitHub issues for adjacent model-provider work. Related but distinct issues include #590 and #589 around explicit provider routing/default-provider behavior, and #157 around OpenRouter as a default provider. I did not find an existing issue for provider-level model approval lists or workflow validation against those lists.

Additional context

Example use case: configure an OpenRouter provider that is allowed for generation, but only when workflows select models from an approved open-source model list. This should be a provider-level guardrail that applies consistently across workflow configs using that provider.

Checklist

• I've reviewed existing issues and the documentation
• This is a design proposal, not a "please build this" request