Add stage planning and placeholder runner

internal/app/app.go

@@ -10,6 +10,7 @@ import (
 	"gitea.maximumdirect.net/eric/narratio/internal/adapters/whisperx"
 	"gitea.maximumdirect.net/eric/narratio/internal/artifacts"
 	"gitea.maximumdirect.net/eric/narratio/internal/config"
+	"gitea.maximumdirect.net/eric/narratio/internal/stage"
 )
 
 // Env is the shared dependency container passed to orchestrator components.
@@ -24,3 +25,20 @@ type Env struct {
 	Analyzer analyzer.Runner
 	Notifier notify.Sender
 }
+
+func toStageEnv(env *Env) *stage.Env {
+	if env == nil {
+		return nil
+	}
+
+	return &stage.Env{
+		Config:        env.Config,
+		ArtifactStore: env.ArtifactStore,
+		Logger:        env.Logger,
+		WhisperX:      env.WhisperX,
+		Seriatim:      env.Seriatim,
+		Audita:        env.Audita,
+		Analyzer:      env.Analyzer,
+		Notifier:      env.Notifier,
+	}
+}