导出step文件合并为整体，方便后续修改

src/core/cad_exporter.py

@@ -29,6 +29,7 @@ import os
 import re
 from typing import Dict, List, Any, Optional, Tuple
 from pathlib import Path
+from OCC.Core.TopoDS import TopoDS_Shape
 from utils.logger import get_logger
 
 logger = get_logger(__name__)
@@ -70,7 +71,7 @@ class CADExporter:
             relative = Path(os.path.basename(filepath))
         return relative.as_posix()
 
-    def export_step(self, shape: Any, filepath: str,
+    def export_step(self, shape: TopoDS_Shape, filepath: str,
                      schema: str = "AP214") -> bool:
         """
         导出 STEP 文件
@@ -118,7 +119,7 @@ class CADExporter:
             logger.error(f"STEP 导出失败: {e}")
             return False
 
-    def export_iges(self, shape: Any, filepath: str) -> bool:
+    def export_iges(self, shape: TopoDS_Shape, filepath: str) -> bool:
         """
         导出 IGES 文件
 
@@ -156,7 +157,7 @@ class CADExporter:
             logger.error(f"IGES 导出失败: {e}")
             return False
 
-    def export_stl(self, shape: Any, filepath: str,
+    def export_stl(self, shape: TopoDS_Shape, filepath: str,
                     ascii_mode: bool = True,
                     deflection: float = 0.1) -> bool:
         """
@@ -201,7 +202,7 @@ class CADExporter:
             logger.error(f"STL 导出失败: {e}")
             return False
 
-    def export_brep(self, shape: Any, filepath: str) -> bool:
+    def export_brep(self, shape: TopoDS_Shape, filepath: str) -> bool:
         """
         导出 BRep 文件（OpenCASCADE 原生格式）
 
@@ -240,18 +241,6 @@ class CADExporter:
                              components: List[str] = None,
                              task_id: Optional[str] = None,
                              scheme_id: Optional[str] = None) -> Dict[str, Any]:
-        """
-        批量导出模具设计结果
-
-        Args:
-            cavity_data: generate_mold_cavities() 的返回结果
-            base_filename: 基础文件名（不含扩展名）
-            formats: 导出格式列表 ["step", "iges", "stl", "brep"]
-            components: 导出组件列表 ["cavity", "core", "parting_surface", "all"]
-
-        Returns:
-            导出结果摘要
-        """
         if formats is None:
             formats = ["step", "stl"]
         if components is None:
@@ -279,7 +268,8 @@ class CADExporter:
             "parting_surface": ("parting_surface", "分型面"),
         }
 
-        shapes_to_export = []
+        shapes_to_export: List[Tuple[str, str, TopoDS_Shape]] = []
+        assembly_shapes: List[Tuple[TopoDS_Shape, str]] = []
 
         for comp in components:
             if comp == "all":
@@ -287,23 +277,45 @@ class CADExporter:
                     shape = cavity_data.get(data_key)
                     if shape is not None:
                         shapes_to_export.append((key, label, shape))
+                        assembly_shapes.append((shape, label))
                 break
             elif comp in shape_map:
                 data_key, label = shape_map[comp]
                 shape = cavity_data.get(data_key)
                 if shape is not None:
                     shapes_to_export.append((comp, label, shape))
+                    assembly_shapes.append((shape, label))
                 else:
                     results["errors"].append(f"{label}形状不可用")
 
+        # STEP: 所有组件合并为一个装配体文件
+        if "step" in formats and assembly_shapes:
+            filepath = os.path.join(export_dir, f"{base_filename}_mold.step")
+            success = self.export_assembly_step(assembly_shapes, filepath)
+            if success:
+                file_size = os.path.getsize(filepath)
+                relative_path = self.get_relative_path(filepath)
+                results["files"].append({
+                    "component": "assembly",
+                    "component_label": "模具装配体",
+                    "format": "step",
+                    "filepath": filepath,
+                    "relative_path": relative_path,
+                    "filename": os.path.basename(filepath),
+                    "size_bytes": file_size,
+                    "size_readable": self._format_file_size(file_size),
+                })
+            else:
+                results["errors"].append("装配体 STEP 导出失败")
+
+        # IGES / STL / BRep: 逐组件导出
+        non_assembly_formats = [f for f in formats if f != "step"]
         for comp_name, label, shape in shapes_to_export:
-            for fmt in formats:
+            for fmt in non_assembly_formats:
                 filepath = os.path.join(export_dir, f"{base_filename}_{comp_name}.{fmt}")
 
                 success = False
-                if fmt == "step":
-                    success = self.export_step(shape, filepath)
-                elif fmt == "iges":
+                if fmt == "iges":
                     success = self.export_iges(shape, filepath)
                 elif fmt == "stl":
                     success = self.export_stl(shape, filepath)
@@ -337,7 +349,7 @@ class CADExporter:
 
         return results
 
-    def export_assembly_step(self, shapes_with_names: List[Tuple[Any, str]],
+    def export_assembly_step(self, shapes_with_names: List[Tuple[TopoDS_Shape, str]],
                               filepath: str,
                               schema: str = "AP214") -> bool:
         """