Initialize CBDD solution and add a .NET-focused gitignore for generated artifacts.

tests/CBDD.Tests/VectorSearchTests.cs

@@ -0,0 +1,31 @@
+using ZB.MOM.WW.CBDD.Bson;
+using ZB.MOM.WW.CBDD.Core;
+using ZB.MOM.WW.CBDD.Core.Indexing;
+using ZB.MOM.WW.CBDD.Shared;
+using Xunit;
+
+namespace ZB.MOM.WW.CBDD.Tests;
+
+public class VectorSearchTests
+{
+    [Fact]
+    public void Test_VectorSearch_Basic()
+    {
+        string dbPath = "vector_test.db";
+        if (File.Exists(dbPath)) File.Delete(dbPath);
+
+        using (var db = new Shared.TestDbContext(dbPath))
+        {
+            db.VectorItems.Insert(new VectorEntity { Title = "Near", Embedding = [1.0f, 1.0f, 1.0f] });
+            db.VectorItems.Insert(new VectorEntity { Title = "Far", Embedding = [10.0f, 10.0f, 10.0f] });
+
+            var query = new[] { 0.9f, 0.9f, 0.9f };
+            var results = db.VectorItems.AsQueryable().Where(x => x.Embedding.VectorSearch(query, 1)).ToList();
+
+            results.Count().ShouldBe(1);
+            results[0].Title.ShouldBe("Near");
+        }
+
+        File.Delete(dbPath);
+    }
+}