A developer must expose a complex business operation—'Recalculate Contract Pricing'—that is triggered from a model-driven form command button, from several Power Automate cloud flows, and from an external system via the Dataverse Web API. The operation must run server-side, participate in the same database transaction as other Dataverse writes, accept typed input parameters, and return a typed response. It should be callable as a single named message across all these consumers. Which Dataverse code component should the developer build?