chore: make it so the small model also is always considered a subagent

This will make it so the quota is not used when generating the title.

internal/agent/coordinator.go

@@ -466,7 +466,7 @@ func (c *coordinator) buildAgentModels(ctx context.Context, isSubAgent bool) (Mo
 		return Model{}, Model{}, errors.New("large model provider not configured")
 	}
 
-	smallProvider, err := c.buildProvider(smallProviderCfg, largeModelCfg, isSubAgent)
+	smallProvider, err := c.buildProvider(smallProviderCfg, largeModelCfg, true)
 	if err != nil {
 		return Model{}, Model{}, err
 	}