fix(v1.0.1): VDE-018 resolved (file clean) + VDE-022 position-based API

VDE-018: Verified — extra braces and invalid using declarations already
removed in prior VDE-016 fix iterations. File compiles clean.

VDE-022: Added brep_position.h/.cpp with position-based lookup:
- get_edge_by_position(body, nearPoint) → edge_id
- get_face_by_position(body, nearPoint) → face_id
- fillet_by_position / chamfer_by_position / shell_by_position

Fixes mesh→BrepModel round-trip ID mismatch for ViewDesign.

include/vde/brep/brep_position.h

@@ -0,0 +1,38 @@
+#pragma once
+#include "vde/brep/brep.h"
+
+namespace vde::brep {
+
+/** @brief 根据几何位置查找最近的边ID
+ *  @param body B-Rep模型
+ *  @param nearPoint 参考点
+ *  @param tolerance 搜索容差（默认1e-6）
+ *  @return 最近边的ID，未找到返回-1
+ */
+int get_edge_by_position(const BrepModel& body, const Point3D& nearPoint, double tolerance = 1e-6);
+
+/** @brief 根据几何位置查找最近的面ID
+ *  @param body B-Rep模型
+ *  @param nearPoint 参考点
+ *  @param tolerance 搜索容差
+ *  @return 最近面的ID，未找到返回-1
+ */
+int get_face_by_position(const BrepModel& body, const Point3D& nearPoint, double tolerance = 1e-6);
+
+/** @brief 基于几何位置的倒圆角
+ *  @param body B-Rep模型
+ *  @param nearPoint 靠近目标边的参考点
+ *  @param radius 圆角半径
+ *  @param tolerance 边搜索容差
+ */
+BrepModel fillet_by_position(const BrepModel& body, const Point3D& nearPoint, double radius, double tolerance = 1e-6);
+
+/** @brief 基于几何位置的倒角
+ */
+BrepModel chamfer_by_position(const BrepModel& body, const Point3D& nearPoint, double distance, double tolerance = 1e-6);
+
+/** @brief 基于几何位置的抽壳
+ */
+BrepModel shell_by_position(const BrepModel& body, const Point3D& nearPoint, double thickness, double tolerance = 1e-6);
+
+}  // namespace vde::brep