Initialize narratio Go module and CLI scaffold

internal/manifest/store.go

@@ -0,0 +1,27 @@
+package manifest
+
+import (
+	"context"
+	"fmt"
+)
+
+// Store is a placeholder interface for manifest persistence.
+type Store interface {
+	Load(ctx context.Context, sessionID string) (*Manifest, error)
+	Save(ctx context.Context, m *Manifest) error
+}
+
+// LocalStore is a placeholder local-filesystem manifest store.
+type LocalStore struct {
+	RootDir string
+}
+
+// Load returns a not-yet-implemented error in the scaffold.
+func (s *LocalStore) Load(_ context.Context, _ string) (*Manifest, error) {
+	return nil, fmt.Errorf("manifest local load: not yet implemented")
+}
+
+// Save returns a not-yet-implemented error in the scaffold.
+func (s *LocalStore) Save(_ context.Context, _ *Manifest) error {
+	return fmt.Errorf("manifest local save: not yet implemented")
+}