Add test infrastructure and repository tests

Introduced `CfgProfileDto` for testing and added a `FakeDataGenerator` utility for generating test data. Updated `ECMJobRunner.Tests.csproj` to support both `.NET Framework 4.8` and `.NET 8.0`, enabling nullable reference types and adding dependencies for testing frameworks, DI, and AutoMapper.

Added `TestFixture` to set up dependency injection and in-memory databases for tests. Created `TestMappingProfile` for AutoMapper configurations. Implemented `CfgProfileRepositoryTests` to validate repository methods, including `GetByIdAsync`, `GetAllAsync`, `AddAsync`, and `FindAsync`.

Enhanced test maintainability with `FluentAssertions` and realistic data generation using `Bogus`.

ECMJobRunner.Tests/Infrastructure/TestFixture.cs

@@ -0,0 +1,81 @@
+using AutoMapper;
+using ECMJobRunner.Domain.Interfaces;
+using ECMJobRunner.Infrastructure;
+using ECMJobRunner.Infrastructure.Data;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Hosting;
+
+namespace ECMJobRunner.Tests.Infrastructure;
+
+/// <summary>
+/// Base test fixture with Dependency Injection and In-Memory Database
+/// Supports both .NET Framework 4.8 (EF6 with Effort) and .NET 8 (EF Core InMemory)
+/// </summary>
+public class TestFixture : IDisposable
+{
+    private readonly IHost _host;
+    private IServiceScope? _scope;
+
+    public IServiceProvider Services => _scope?.ServiceProvider ?? _host.Services;
+    public JobRunnerDbContext DbContext => Services.GetRequiredService<JobRunnerDbContext>();
+    public IMapper Mapper => Services.GetRequiredService<IMapper>();
+    public ICfgProfileRepository ProfileRepository => Services.GetRequiredService<ICfgProfileRepository>();
+    public IProfileSqlJobRepository SqlJobRepository => Services.GetRequiredService<IProfileSqlJobRepository>();
+    public IProfileHistoryRepository HistoryRepository => Services.GetRequiredService<IProfileHistoryRepository>();
+
+    public TestFixture()
+    {
+        _host = Host.CreateDefaultBuilder()
+            .ConfigureServices((context, services) =>
+            {
+                // Use AddInfrastructureInMemory extension for both frameworks
+                services.AddInfrastructureInMemory();
+                
+                // Register test-specific AutoMapper profiles
+                services.AddAutoMapper(typeof(TestFixture).Assembly);
+            })
+            .Build();
+
+        // Create a scope for scoped services
+        _scope = _host.Services.CreateScope();
+
+#if !NET48
+        // Ensure database is created (EF Core only)
+        DbContext.Database.EnsureCreated();
+#endif
+    }
+
+    /// <summary>
+    /// Create a new service scope (useful for testing scoped lifetime)
+    /// </summary>
+    public IServiceScope CreateScope()
+    {
+        return _host.Services.CreateScope();
+    }
+
+    /// <summary>
+    /// Reset the current scope (creates a new DbContext)
+    /// </summary>
+    public void ResetScope()
+    {
+        _scope?.Dispose();
+        _scope = _host.Services.CreateScope();
+    }
+
+    /// <summary>
+    /// Clear all data from database
+    /// </summary>
+    public async Task ClearDatabaseAsync()
+    {
+        DbContext.ProfileHistories.RemoveRange(DbContext.ProfileHistories);
+        DbContext.ProfileSqlJobs.RemoveRange(DbContext.ProfileSqlJobs);
+        DbContext.CfgProfiles.RemoveRange(DbContext.CfgProfiles);
+        await DbContext.SaveChangesAsync();
+    }
+
+    public void Dispose()
+    {
+        _scope?.Dispose();
+        _host?.Dispose();
+    }
+}