fix(dolt): prevent daemon startup and fix routing same-dir check

- Daemon now refuses to start when dolt backend is configured
  (dolt uses sql-server mode, not the SQLite daemon)
- Add same-directory check in GetRoutedStorageWithOpener to avoid
  opening duplicate connections when routing resolves to current dir

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

internal/routing/routes.go

@@ -455,6 +455,11 @@ func GetRoutedStorageWithOpener(ctx context.Context, id, currentBeadsDir string,
 		return nil, nil // No routing needed, caller should use existing storage
 	}
 
+	// Check if target is same as current - no need to open a new store
+	if beadsDir == currentBeadsDir {
+		return nil, nil // Same directory, caller should use existing storage
+	}
+
 	// Open storage for the routed directory
 	var store storage.Storage
 	if opener != nil {