Add integration test project with MediatR procedure tests

Added ReC.Tests project with integration tests for stored procedure commands and queries via MediatR, covering endpoints, actions, results, and profiles. Introduced a test base for DI/configuration, helper for private property access, and updated the solution to include the new test suite. Tests use NUnit and cover both positive and negative scenarios.

tests/ReC.Tests/Application/RecActions/RecActionQueryTests.cs

@@ -0,0 +1,55 @@
+using System.Linq;
+using System.Threading.Tasks;
+using DigitalData.Core.Exceptions;
+using MediatR;
+using Microsoft.Extensions.Configuration;
+using Microsoft.Extensions.DependencyInjection;
+using NUnit.Framework;
+using ReC.Application.RecActions.Queries;
+using ReC.Tests.Application;
+
+namespace ReC.Tests.Application.RecActions;
+
+[TestFixture]
+public class RecActionQueryTests : RecApplicationTestBase
+{
+    private (ISender Sender, IServiceScope Scope) CreateScopedSender()
+    {
+        var scope = ServiceProvider.CreateScope();
+        var sender = scope.ServiceProvider.GetRequiredService<ISender>();
+        return (sender, scope);
+    }
+
+    [Test]
+    public async Task ReadRecActionViewQuery_returns_actions_for_profile()
+    {
+        var profileId = Configuration.GetValue<long?>("FakeProfileId");
+        Assert.That(profileId, Is.Not.Null.And.GreaterThan(0), "FakeProfileId must be configured in appsettings.json");
+
+        var (sender, scope) = CreateScopedSender();
+        using var _ = scope;
+
+        var actions = await sender.Send(new ReadRecActionViewQuery
+        {
+            ProfileId = profileId
+        });
+
+        Assert.That(actions, Is.Not.Empty);
+        Assert.That(actions.All(a => a.ProfileId == profileId));
+    }
+
+    [Test]
+    public void ReadRecActionViewQuery_with_unknown_profile_throws_not_found()
+    {
+        var (sender, scope) = CreateScopedSender();
+        using var _ = scope;
+
+        var invalidProfileId = long.MaxValue;
+
+        Assert.ThrowsAsync<NotFoundException>(async () =>
+            await sender.Send(new ReadRecActionViewQuery
+            {
+                ProfileId = invalidProfileId
+            }));
+    }
+}