导出step文件合并为整体，方便后续修改

src/core/multi_scheme_planner.py

@@ -6,7 +6,7 @@ from OCC.Core.GProp import GProp_GProps
 from OCC.Core.gp import gp_Dir, gp_Pln, gp_Pnt
 from OCC.Core.TopAbs import TopAbs_FACE
 from OCC.Core.TopExp import TopExp_Explorer
-from OCC.Core.TopoDS import TopoDS_Face, topods
+from OCC.Core.TopoDS import TopoDS_Face, TopoDS_Shape, topods
 
 from core.mold_generator import MoldCavityGenerator
 from core.aluminum_foam_mold import AluminumFoamMoldGenerator
@@ -31,7 +31,7 @@ class MultiSchemeMoldPlanner:
 
     def generate_plan(
         self,
-        shape: Any,
+        shape: TopoDS_Shape,
         material: Dict[str, Any],
         is_foam_material: bool = False,
         max_schemes: int = 3,
@@ -92,7 +92,7 @@ class MultiSchemeMoldPlanner:
     def _build_scheme(
         self,
         generator: Any,
-        shape: Any,
+        shape: TopoDS_Shape,
         analysis: Dict[str, Any],
         candidate: Dict[str, Any],
         is_foam_material: bool,
@@ -209,10 +209,10 @@ class MultiSchemeMoldPlanner:
         generator: Any,
         analysis: Dict[str, Any],
         direction_vector: List[float],
-        shape: Any,
+        shape: TopoDS_Shape,
         offset_ratio: float = 0.0,
         opening_span_mm: Optional[float] = None,
-    ) -> Any:
+    ) -> TopoDS_Face:
         center = analysis.get("bounding_box", {}).get("center", [0, 0, 0])
         dims = analysis.get("bounding_box", {}).get("dimensions", [100, 100, 100])
         span = max(dims) * 1.5 + 30
@@ -272,7 +272,7 @@ class MultiSchemeMoldPlanner:
 
         return variants
 
-    def _collect_axis_normal_stats(self, generator: Any, shape: Any) -> Dict[str, float]:
+    def _collect_axis_normal_stats(self, generator: Any, shape: TopoDS_Shape) -> Dict[str, float]:
         """按坐标轴统计面法向分布强度，用于候选方向排序。"""
         stats = {"X": 0.0, "Y": 0.0, "Z": 0.0}
         explorer = TopExp_Explorer(shape, TopAbs_FACE)