Caller options containing optional provider and/or model.
Task type used to select the correct default model. Defaults to "text".
A ParsedModel with providerId and modelId.
When no provider can be determined, the provider is unknown, or the provider has no default model for the requested task.
Resolves a
{ providerId, modelId }pair from flexible caller-supplied options.Resolution priority:
modelstring — if it contains":"it is split directly (backwards-compatibleprovider:modelformat). If it is a plain name andprovideris set, the pair is used as-is. If neither, auto-detection from env vars is attempted.provideronly — default model for the requestedtaskis looked up in PROVIDER_DEFAULTS.task.