Add stage planning and placeholder runner

internal/app/plan.go

@@ -10,15 +10,17 @@ import (
 	"gitea.maximumdirect.net/eric/narratio/internal/config"
 )
 
-// Plan validates configuration inputs and prepares the local session workdir.
+// Plan validates configuration, prepares the local workdir, and prints stage order.
 func Plan(_ context.Context, args []string, out io.Writer) error {
 	fs := flag.NewFlagSet("plan", flag.ContinueOnError)
 	fs.SetOutput(io.Discard)
 
 	var pipelinePath string
 	var sessionPath string
+	var force bool
 	fs.StringVar(&pipelinePath, "config", "", "path to pipeline.yml")
 	fs.StringVar(&sessionPath, "session", "", "path to session.yml")
+	fs.BoolVar(&force, "force", false, "force stage execution (reserved for future behavior)")
 
 	if err := fs.Parse(args); err != nil {
 		return fmt.Errorf("plan: invalid flags: %w", err)
@@ -44,6 +46,17 @@ func Plan(_ context.Context, args []string, out io.Writer) error {
 		return fmt.Errorf("plan: prepare workdir: %w", err)
 	}
 
-	_, err = fmt.Fprintf(out, "narratio plan: configuration loaded and valid; workdir prepared at %s\n", paths.Root)
-	return err
+	_ = force // TODO: use --force in future skip/stale planning behavior.
+
+	stages := BuildFullPlan()
+	if _, err := fmt.Fprintf(out, "narratio plan: workdir prepared at %s\n", paths.Root); err != nil {
+		return err
+	}
+	for _, s := range stages {
+		if _, err := fmt.Fprintln(out, s.Name()); err != nil {
+			return err
+		}
+	}
+
+	return nil
 }