feat(cadfs): 补齐核心建模能力并建立代表性回归

- 新增 loft、双向切除、through-all/up-to-next 等 CADFS lowering 与 engine 支持
- 支持多种 reference plane、B-spline profile 和 circular pattern replay
- 保留 transform 历史，并烘焙安全的单源平移/旋转变换
- 改进 selector 绑定、拓扑快照和 pattern 变换处理
- 建立 17 个代表样本的转换、重建与比较回归工具链
- 补充 schema、author guidance、运行时和几何回归测试

backend/engine/cdsl_engine/build123d_adapter.py

@@ -65,9 +65,15 @@ class Build123dGeometryAdapter:
 
     @staticmethod
     def _wire(edges: list[dict[str, Any]]) -> Wire:
-        # 将边字典列表（直线/圆弧）组装成 build123d 的 Wire 线框。
+        # 将边字典列表（直线/圆弧/插值 B 样条）组装成 build123d 的 Wire 线框。
         built: list[Edge] = []
         for edge in edges:
+            if edge.get("type") == "bspline":
+                points = [_vector(point) for point in edge.get("points_mm") or []]
+                if len(points) < 3:
+                    raise ValueError("bspline contour edge needs at least 3 points")
+                built.append(Edge.make_spline(points, periodic=False))
+                continue
             start = _vector(edge["start_mm"])
             end = _vector(edge["end_mm"])
             if edge.get("type") == "arc" and edge.get("center_mm") is not None:
@@ -133,20 +139,38 @@ class Build123dGeometryAdapter:
             result: list[Face] = []
             for region in regions:
                 outer = region.get("outer") or []
-                if len(outer) < 2:
+                # 闭合插值样条仅有一条边；直线/圆弧轮廓通常由多条边组成。
+                if len(outer) < 1:
                     continue
                 face = Face(self._wire(outer))
-                holes = [self._wire(hole) for hole in region.get("holes") or [] if len(hole) >= 2]
+                holes = [self._wire(hole) for hole in region.get("holes") or [] if len(hole) >= 1]
                 result.append(face.make_holes(holes) if holes else face)
             return result
         # 2. 退化：仅有单组轮廓边时，直接作为外轮廓建面。
         edges = sketch.get("contour_edges_mm") or []
-        if len(edges) >= 2:
+        if len(edges) >= 1:
             return [Face(self._wire(edges))]
         # 3. 最终回退：由工作平面与实体圆生成面（圆环/孔洞处理见 _faces_from_circles）。
         plane = PlaneSpec.from_mapping(sketch.get("workplane") or {})
         return self._faces_from_circles(sketch.get("entities") or [], plane)
 
+    def loft(self, sketches: list[dict[str, Any]]) -> Solid:
+        """由多条简单闭合草图轮廓生成实体放样。"""
+        wires: list[Wire] = []
+        for index, sketch in enumerate(sketches):
+            # Solid.make_loft 接收 Wire；复用 faces_for_sketch 保持放样、
+            # 拉伸和回转的 profile resolver 一致。多区域/内环的截面对应关系
+            # 尚未由 CDSL 表达，必须显式拒绝而非猜测。
+            faces = self.faces_for_sketch(sketch)
+            if len(faces) != 1:
+                raise ValueError(f"loft profile {index} must resolve to exactly one closed region")
+            if faces[0].inner_wires():
+                raise ValueError(f"loft profile {index} must not contain inner loops")
+            wires.append(faces[0].outer_wire())
+        if len(wires) < 2:
+            raise ValueError("loft requires at least two profile sketches")
+        return Solid.make_loft(wires)
+
     @staticmethod
     def _coerce_single_or_compound(result: Any, *, empty_error: str | None = None) -> Any:
         """规整一次布尔结果：None/空视为失败（可选报错），多成员合并为 Compound。"""
@@ -188,14 +212,22 @@ class Build123dGeometryAdapter:
         """
         # 1. 采样点到目标的最远命中距离决定穿透余量；没有任何采样点命中
         #    说明 profile 与目标面无交叠，无法裁剪（保留 extent_target_not_reached）。
+        #    through_next 的 target 是当前主体，必须先从其面中选出实际命中的
+        #    下一终止面，不能把整个 body 当作待拉伸的 Face。
         unit = _vector(direction).normalized()
-        hits = [
-            Build123dGeometryAdapter._forward_intersection_distance(target, point, unit)
-            for point in Build123dGeometryAdapter.profile_sample_points(face)
-        ]
-        distances = [value for value in hits if value is not None]
-        if not distances:
+        points = Build123dGeometryAdapter.profile_sample_points(face)
+        targets = [target] if isinstance(target, Face) else list(target.faces())
+        candidates = []
+        for candidate in targets:
+            hits = [Build123dGeometryAdapter._forward_intersection_distance(candidate, point, unit) for point in points]
+            distances = [value for value in hits if value is not None]
+            if distances:
+                candidates.append((len(distances), min(distances), candidate, distances))
+        if not candidates:
             raise ValueError("extent target is not reached by the profile")
+        # 覆盖最多 profile 采样点的面就是本次实体的下一终止面；覆盖数相同
+        # 时取最近的正向交点，确保相邻面交界处的选择稳定。
+        _, _, target, distances = max(candidates, key=lambda item: (item[0], -item[1]))
         margin = max(distances) + 2.0
         # 2. 穿透拉伸 profile，同时把目标面向回推生成体层，二者求交即裁剪体。
         #    build123d 的布尔交方法名是 intersect（不是 OCC 的 common），