Add in-memory DB support for .NET 4.8 and .NET 8 testing

Introduced a `DbConnection` constructor in `JobRunnerDbContext`
for Entity Framework 6 to enable in-memory testing with the
Effort library. Added conditional compilation to support both
.NET Framework 4.8 and .NET 8.

Implemented `AddInfrastructureInMemory` in `DependencyExtension`
to register services with in-memory databases:
- For .NET 4.8, uses Effort's transient connection.
- For .NET 8, uses EF Core's in-memory provider.

Registered AutoMapper in both methods for object mapping. Added
`EntityMappingProfile` to define AutoMapper configurations,
enforcing explicit DTO-to-entity mappings. These changes improve
testability and maintainability across .NET versions.

ECMJobRunner.Infrastructure/Data/JobRunnerDbContext.cs

@@ -1,5 +1,6 @@
 #if NET48
 using System.Data.Entity;
+using System.Data.Common;
 #else
 using Microsoft.EntityFrameworkCore;
 #endif
@@ -41,6 +42,13 @@ namespace ECMJobRunner.Infrastructure.Data
         public JobRunnerDbContext(string connectionString) : base(connectionString)
         {
         }
+
+        /// <summary>
+        /// Constructor with DbConnection for Entity Framework 6 (used for InMemory testing with Effort)
+        /// </summary>
+        public JobRunnerDbContext(DbConnection connection) : base(connection, contextOwnsConnection: true)
+        {
+        }
 #else
         /// <summary>
         /// Constructor for Entity Framework Core (.NET 8)