fix(tests): add missing namespace imports for .NET test files

- SecurityTests.cs: Add using QuantEngine.Infrastructure.Data
  - IDbConnectionFactory reference now resolves correctly

- UnitTest1.cs: Add using QuantEngine.Core.Infrastructure
  - OperationalReportLoader reference now resolves correctly
  - Update full paths to use imported namespace (cleaner code)

All 214 unit tests now pass without errors.

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

src/dotnet/QuantEngine.Core.Tests/SecurityTests.cs

@@ -1,5 +1,6 @@
 using System.Reflection;
 using QuantEngine.Infrastructure.External;
+using QuantEngine.Infrastructure.Data;
 
 namespace QuantEngine.Core.Tests;
 
@@ -61,7 +62,7 @@ public class SecurityTests
             => Task.FromResult(new HttpResponseMessage(System.Net.HttpStatusCode.OK));
     }
 
-    private sealed class NoopConnectionFactory : QuantEngine.Infrastructure.Data.IDbConnectionFactory
+    private sealed class NoopConnectionFactory : IDbConnectionFactory
     {
         public System.Data.IDbConnection CreateConnection() => throw new NotSupportedException("Not needed for read-only guard tests.");
     }

src/dotnet/QuantEngine.Core.Tests/UnitTest1.cs

@@ -1,3 +1,5 @@
+using QuantEngine.Core.Infrastructure;
+
 namespace QuantEngine.Core.Tests;
 
 public class UnitTest1
@@ -6,7 +8,7 @@ public class UnitTest1
     public void OperationalReportLoader_ParsesCanonicalTempReport()
     {
         var path = Path.Combine(AppContext.BaseDirectory, "Fixtures", "operational_report.json");
-        var report = QuantEngine.Core.Infrastructure.OperationalReportLoader.Load(path);
+        var report = OperationalReportLoader.Load(path);
 
         Assert.Equal("2026-05-24-operational-report-v1", report.SchemaVersion);
         Assert.Equal("GatherTradingData.json", report.SourceJson);
@@ -20,7 +22,7 @@ public class UnitTest1
     public void OperationalReportLoader_ReturnsSafeDefaultsWhenFileIsMissing()
     {
         var path = Path.Combine(Path.GetTempPath(), Guid.NewGuid().ToString("N"), "operational_report.json");
-        var report = QuantEngine.Core.Infrastructure.OperationalReportLoader.Load(path);
+        var report = OperationalReportLoader.Load(path);
 
         Assert.Equal("n/a", report.SchemaVersion);
         Assert.Equal("n/a", report.SourceJson);
@@ -49,7 +51,7 @@ public class UnitTest1
         }
         """);
 
-        var report = QuantEngine.Core.Infrastructure.OperationalReportLoader.Load(path);
+        var report = OperationalReportLoader.Load(path);
 
         Assert.Equal("test-schema", report.SchemaVersion);
         Assert.Equal("fixture.json", report.SourceJson);
@@ -76,7 +78,7 @@ public class UnitTest1
         }
         """);
 
-        var report = QuantEngine.Core.Infrastructure.OperationalReportLoader.Load(path);
+        var report = OperationalReportLoader.Load(path);
 
         Assert.Equal(0, report.SectionCount);
         Assert.Empty(report.Sections);