Service
data class Service(val llmService: LlmService<*>, val llmOptions: LlmOptions = LlmOptions.withDefaults()) : RoleResolution
An already-built service, for callers that construct their own.
llmOptions travels with it and is merged the way Options is, so a resolver that built its own service does not have to give up the tuning configured beside the model name. Defaulted, because a resolver handing back a service it configured itself has nothing to add.