Improve testing and some cleanup refactoring.

wolverine/a-frame-architecture/FinancialApi.Infrastructure/AccountDbContext.cs

@@ -16,9 +16,9 @@ public class AccountDbContext(DbContextOptions<AccountDbContext> options) : DbCo
 
         modelBuilder.Entity<Account>()
             .HasData(
-                new Account(1, 10000000.00m, "Credit"),
-                new Account(2, 50000000.00m, "Liability"),
-                new Account(99999, 0.00m, "Revenue")
+                new Account(1, 10000000.00m, AccountType.Credit),
+                new Account(2, 50000000.00m, AccountType.Liability),
+                new Account(99999, 0.00m, AccountType.Revenue)
             );
 
         modelBuilder.Entity<JournalEntry>(builder =>