feat: 完善一级关系编辑 UI 与视图体验

step_editor/model.py

@@ -127,6 +127,7 @@ class StepModel(FeatureMixin, ExportMixin, TransformMixin, OperationMixin, Polyd
         self._edge_polydata_cache: dict[tuple[object, ...], object] = {}
         self._polydata_cache_limit = 96
         self._mesh_deflection: float | None = None
+        self._face_mesh_deflections: dict[int, float] = {}
         self.refresh_topology()
 
     @classmethod
@@ -214,6 +215,7 @@ class StepModel(FeatureMixin, ExportMixin, TransformMixin, OperationMixin, Polyd
         self._face_polydata_cache.clear()
         self._edge_polydata_cache.clear()
         self._mesh_deflection = None
+        self._face_mesh_deflections.clear()
 
         solid_id = 0
         for part in self.display_parts():