Enable bundled OpenRouter configuration by default

internal/engine/engine.go

@@ -41,13 +41,17 @@ type ConfigurationSources struct {
 
 // Options collects construction choices from the public facade.
 type Options struct {
-	llmClient       llm.Client
-	artifactReader  artifact.Reader
-	validator       validate.Validator
-	validatorSource bool
-	artifactSource  bool
+	llmClient                llm.Client
+	artifactReader           artifact.Reader
+	validator                validate.Validator
+	validatorSource          bool
+	artifactSource           bool
+	disableBundledOpenRouter bool
 }
 
+// SetBundledOpenRouter selects whether the built-in OpenRouter source is installed.
+func (o *Options) SetBundledOpenRouter(enabled bool) { o.disableBundledOpenRouter = !enabled }
+
 // SetLLMClient selects the client collaborator for one engine.
 func (o *Options) SetLLMClient(client llm.Client) { o.llmClient = client }
 
@@ -124,6 +128,11 @@ func New(cfg Config, options Options) (*Engine, error) {
 		return nil, err
 	}
 	underlays := cfg.Sources.Underlays
+	if !options.disableBundledOpenRouter {
+		underlays = make([]configkit.Underlay, 1, len(cfg.Sources.Underlays)+1)
+		underlays[0] = configuration.BundledOpenRouterUnderlay()
+		underlays = append(underlays, cfg.Sources.Underlays...)
+	}
 	main := configkit.Input{Source: configkit.NoSource()}
 	if cfg.Sources.Main != nil {
 		main = *cfg.Sources.Main