fix: ensure default model is parsed when using default model provider

When using the default model provider flag, the default model will be
gpt-4o. However, when it is parsed, the expected format is 'gpt-4p from
my-model-provider'. When using a default model provider, the 'gpt-4o'
was being parsed and the model was set to the empty string.

After this change, the default model will be of the form 'default-model
from default-model-provider' and will be parsed properly.

Signed-off-by: Donnie Adams <donnie@acorn.io>

Author: thedadams

pkg/cli/gptscript.go

@@ -231,6 +231,9 @@ func (r *GPTScript) PersistentPre(*cobra.Command, []string) error {
 	if r.DefaultModel != "" {
 		builtin.SetDefaultModel(r.DefaultModel)
 	}
+	if r.DefaultModelProvider != "" {
+		builtin.SetDefaultModel(fmt.Sprintf("%s from %s", builtin.GetDefaultModel(), r.DefaultModelProvider))
+	}
 
 	if r.Quiet == nil {
 		if term.IsTerminal(int(os.Stdout.Fd())) {