fix(conductor): Resolve FileExistsError and harden Preset Manager modal

src/presets.py

@@ -84,6 +84,8 @@ class PresetManager:
    return {"presets": {}}
 
  def _save_file(self, path: Path, data: Dict[str, Any]) -> None:
+  if path.parent.exists() and path.parent.is_file():
+   raise ValueError(f"Cannot save to {path}: Parent directory {path.parent} is a file. The project root seems to be a file.")
   path.parent.mkdir(parents=True, exist_ok=True)
   with open(path, "wb") as f:
    f.write(tomli_w.dumps(data).encode("utf-8"))