feat(v8): ultimate performance + CAM full optimization + visualization/IGA/quality

v8.1 — 极致性能 (SIMD + LockFree + Transaction + NUMA):
- simd_vector.h: Vec4d/Vec4f SSE/AVX/NEON auto-detect, batch AABB, SoA transpose
- concurrent_data: LockFreeQueue (MPMC CAS), LockFreeStack (Treiber), ConcurrentHashMap (64-segment sharded)
- transaction: Command pattern, UndoManager (infinite undo/redo), crash-recovery journal
- performance_tuning: NUMA-aware, cache_line aligned, prefetch, hot/cold separation
- 20 tests (concurrent + transaction), ~2600 lines

v8.2 — CAM 全面优化 + 装配模式:
- cam_optimization: chip_thinning, HSM, constant_engagement, trochoidal_turn_milling
- tool_life_management, probing_cycle, thread_milling
- cam_advanced enhanced: Mazak/Okuma/Haas/DMG post-processors (8 total)
- assembly_patterns: Circular/Rectangular/Mirror/PatternDriven/fill arrays
- assembly_feature enhanced: assembly-level PMI propagation, batch interference check
- 28 tests, compiled 0 errors (~2800 lines)

v8.3 — 可视化+压缩+IGA+质量闭环:
- visualization_quality: ambient_occlusion, edge_highlighting, wireframe, normals
- topology_compression: Brep compression, Edgebreaker, vertex quantization
- iga_prep: knot_insertion, degree_elevation, Bezier extraction for IGA analysis
- quality_feedback: design_rule_check, manufacturability, cost_estimation, quality_score (0-100)
- 28 tests, ~2349 lines

27 files, ~7750 lines, 76 tests

include/vde/mesh/visualization_quality.h

@@ -0,0 +1,130 @@
+#pragma once
+/**
+ * @file visualization_quality.h
+ * @brief 网格可视化增强与质量评估
+ *
+ * 提供环境光遮蔽、硬边检测/高亮、线框叠加、法线可视化等渲染辅助数据。
+ * 所有函数输出纯数据（颜色数组、线段数组等），由渲染管线消费。
+ *
+ * @ingroup mesh
+ */
+#include "vde/mesh/halfedge_mesh.h"
+#include "vde/core/point.h"
+#include <vector>
+#include <array>
+#include <utility>
+#include <cstdint>
+
+namespace vde::mesh {
+using core::Point3D;
+using core::Vector3D;
+
+// ═══════════════════════════════════════════════════════════
+//  数据结构
+// ═══════════════════════════════════════════════════════════
+
+/// 逐顶点 AO 值
+struct AOResult {
+    std::vector<double> vertex_ao;    ///< 逐顶点环境光遮蔽因子 [0,1]（1=完全暴露）
+    double              min_ao;       ///< 最小 AO 值
+    double              max_ao;       ///< 最大 AO 值
+    double              avg_ao;       ///< 平均 AO 值
+    int                 samples;      ///< 实际采样数
+};
+
+/// 硬边检测结果
+struct EdgeHighlightResult {
+    std::vector<std::pair<int,int>> hard_edges;  ///< 硬边：(vA, vB) 顶点索引对
+    std::vector<double>             edge_angles; ///< 对应二面角（弧度）
+    double                          angle_threshold; ///< 使用的角度阈值
+    int                             total_edges; ///< 检测总边数
+    int                             hard_count;  ///< 硬边数
+};
+
+/// 线框叠加线段
+struct WireframeOverlay {
+    std::vector<std::pair<int,int>> wire_edges;   ///< 线框边：(vA, vB)
+    std::vector<Point3D>            vertices;     ///< 顶点坐标
+};
+
+/// 法线可视化数据
+struct NormalVisData {
+    std::vector<Point3D>  face_centers;   ///< 面中心
+    std::vector<Vector3D> face_normals;   ///< 面法线
+    std::vector<Point3D>  vertex_positions; ///< 顶点位置
+    std::vector<Vector3D> vertex_normals; ///< 顶点法线（平均面法线）
+};
+
+// ═══════════════════════════════════════════════════════════
+//  环境光遮蔽
+// ═══════════════════════════════════════════════════════════
+
+/**
+ * @brief 计算逐顶点环境光遮蔽（Ambient Occlusion）
+ *
+ * 对每个顶点在其上半球采样 `samples` 条射线，统计被遮挡比例。
+ * AO = 1 - (被遮挡射线数 / 总射线数)。
+ *
+ * @param mesh    三角网格
+ * @param samples 每顶点采样射线数（默认 128，越多越精确）
+ * @return AOResult 包含逐顶点 AO 值及统计信息
+ *
+ * @ingroup mesh
+ */
+AOResult ambient_occlusion(const HalfedgeMesh& mesh, int samples = 128);
+
+// ═══════════════════════════════════════════════════════════
+//  边高亮（硬边检测）
+// ═══════════════════════════════════════════════════════════
+
+/**
+ * @brief 检测硬边（二面角超过阈值的边）
+ *
+ * 遍历网格所有边，计算相邻两面的二面角，
+ * 角度超过 angle_threshold（弧度）的边标记为硬边。
+ *
+ * @param mesh            三角网格
+ * @param angle_threshold 硬边阈值（弧度），默认 π/4 = 45°
+ * @return EdgeHighlightResult
+ *
+ * @ingroup mesh
+ */
+EdgeHighlightResult edge_highlighting(const HalfedgeMesh& mesh,
+                                        double angle_threshold = 0.785398163);
+
+// ═══════════════════════════════════════════════════════════
+//  线框叠加
+// ═══════════════════════════════════════════════════════════
+
+/**
+ * @brief 提取线框叠加数据
+ *
+ * 从实体网格提取所有唯一边，生成线框表示。
+ * 可选地排除与 solid_mesh 重合的边（只显示差异边）。
+ *
+ * @param mesh       三角网格
+ * @param solid_mesh 实体网格（空网格 = 忽略）
+ * @return WireframeOverlay
+ *
+ * @ingroup mesh
+ */
+WireframeOverlay wireframe_overlay(const HalfedgeMesh& mesh,
+                                    const HalfedgeMesh& solid_mesh = HalfedgeMesh());
+
+// ═══════════════════════════════════════════════════════════
+//  法线可视化
+// ═══════════════════════════════════════════════════════════
+
+/**
+ * @brief 生成法线可视化数据
+ *
+ * 计算每个面的中心点与法线、每个顶点法线（相邻面法线的面积加权平均）。
+ *
+ * @param mesh 三角网格
+ * @return NormalVisData
+ *
+ * @ingroup mesh
+ */
+NormalVisData normal_visualization(const HalfedgeMesh& mesh);
+
+}  // namespace vde::mesh