fix: Delaunay3D circumcenter 完整实现 + 测试恢复

bench/bench_delaunay.cpp

@@ -0,0 +1,35 @@
+/// bench_delaunay.cpp — 2D Delaunay triangulation benchmarks
+///
+/// Metrics:
+///   Delaunay2D/N{size} — Bowyer-Watson triangulation time for N random points
+
+#include <benchmark/benchmark.h>
+#include <vde/mesh/delaunay_2d.h>
+#include <random>
+#include <vector>
+
+using namespace vde;
+
+namespace {
+
+std::vector<core::Point2D> random_points_2d(int n, double R = 1000.0) {
+    std::mt19937 rng(42);
+    std::uniform_real_distribution<double> dist(-R, R);
+    std::vector<core::Point2D> pts;
+    pts.reserve(n);
+    for (int i = 0; i < n; ++i)
+        pts.emplace_back(dist(rng), dist(rng));
+    return pts;
+}
+
+} // namespace
+
+static void Delaunay2D(benchmark::State& state) {
+    auto pts = random_points_2d(state.range(0));
+    for (auto _ : state) {
+        auto result = mesh::delaunay_2d(pts);
+        benchmark::DoNotOptimize(result.triangles.size());
+    }
+    state.SetItemsProcessed(state.iterations() * state.range(0));
+}
+BENCHMARK(Delaunay2D)->Arg(100)->Arg(1000)->Arg(10000);