feat: Python 绑定 — pybind11 核心/曲线/网格模块

- 使用 pybind11 v2.11.1 (FetchContent) 构建 _vde 原生模块
- 模块化结构: bind_core.cpp / bind_curves.cpp / bind_mesh.cpp
- 暴露核心类型: Point2D, Point3D, Vector3D, AABB3D, Polygon2D
- 暴露曲线: BezierCurve, BSplineCurve, NurbsCurve
- 暴露网格: delaunay_2d/3d, DelaunayResult, HalfedgeMesh
- 变换函数: translate, rotate, scale 等
- Python 包 vde/ 含 __init__.py 及子模块封装
- setup.py 支持 pip install -e . 可编辑安装
- VDE_BUILD_PYTHON CMake 选项 (默认 OFF)，通过 -DVDE_BUILD_PYTHON=ON 启用

python/vde/core.py

@@ -0,0 +1,41 @@
+"""
+vde.core — Core geometry types and operations.
+
+Re-exports from the native _vde.core submodule:
+    Point2D, Point3D, Vector3D, AABB3D, Polygon2D
+    distance, convex_hull_2d, convex_hull_3d
+    translate, rotate, rotate_x, rotate_y, rotate_z, scale
+"""
+from vde._vde.core import (
+    Point2D,
+    Point3D,
+    Vector3D,
+    AABB3D,
+    Polygon2D,
+    distance,
+    convex_hull_2d,
+    convex_hull_3d,
+    translate,
+    rotate,
+    rotate_x,
+    rotate_y,
+    rotate_z,
+    scale,
+)
+
+__all__ = [
+    "Point2D",
+    "Point3D",
+    "Vector3D",
+    "AABB3D",
+    "Polygon2D",
+    "distance",
+    "convex_hull_2d",
+    "convex_hull_3d",
+    "translate",
+    "rotate",
+    "rotate_x",
+    "rotate_y",
+    "rotate_z",
+    "scale",
+]