fix: add pint call to enforce initialization of unit registry (#1146)

Workaround for hgrecco/pint#2039

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

- **New Features**
- Integrated `pint` library for unit management, improving flexibility
and precision in handling measurements.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

package/PartSeg/common_backend/base_settings.py

@@ -13,6 +13,7 @@
 
 import napari.utils.theme
 import numpy as np
+import pint
 from napari.qt import get_stylesheet
 from napari.utils import Colormap
 from napari.utils.theme import get_theme
@@ -471,6 +472,7 @@ def __init__(self, json_path: Union[Path, str], profile_name: str = "default"):
         self.history_index = -1
         self.last_executed_algorithm = ""
         self._points = None
+        pint.get_application_registry()("nm")  # enforce pint registry initialization
 
     def _image_changed(self):
         super()._image_changed()