Remove EGDbContextFactory and related configuration code

The `EGDbContextFactory` class, which implemented the
`IDesignTimeDbContextFactory<EGDbContext>` interface, has been
removed. This includes the `CreateDbContext` method, which handled
design-time DbContext creation by loading configuration from
`appsettings.migration.json`, setting up `DbContextOptions`, and
constructing `DbTriggerParams`.

Additionally, the `#if NET` preprocessor directive and its
corresponding `#endif` have been removed, along with all associated
`using` directives. This change suggests that the factory is no
longer needed due to a shift in the application's architecture or
design-time DbContext handling.

EnvelopeGenerator.Infrastructure/EGDbContextFactory.cs

@@ -1,48 +0,0 @@
-#if NET
-using EnvelopeGenerator.Application.Common.Configurations;
-using Microsoft.EntityFrameworkCore;
-using Microsoft.EntityFrameworkCore.Design;
-using Microsoft.Extensions.Configuration;
-using Microsoft.Extensions.Options;
-
-namespace EnvelopeGenerator.Infrastructure
-{
-    public class EGDbContextFactory : IDesignTimeDbContextFactory<EGDbContext>
-    {
-        public EGDbContext CreateDbContext(string[] args)
-        {
-            var config = new ConfigurationBuilder()
-                .SetBasePath(Directory.GetCurrentDirectory())
-                .AddJsonFile("appsettings.migration.json")
-                .Build();
-
-            // create DbContextOptions
-            var optionsBuilder = new DbContextOptionsBuilder<EGDbContext>();
-            optionsBuilder.UseSqlServer(config.GetConnectionString("Default"));
-
-            // create DbTriggerParams
-            var triggerLists = config.GetSection("DbTriggerParams").Get<Dictionary<string, List<string>>>();
-            var dbTriggerParams = new DbTriggerParams();
-            if (triggerLists is not null)
-                foreach (var triggerList in triggerLists)
-                {
-                    if (triggerList.Value.Count == 0)
-                        continue; // Skip empty trigger lists
-
-                    var tableName = triggerList.Key;
-
-                    dbTriggerParams[tableName] = new List<string>();
-
-                    foreach (var trigger in triggerList.Value)
-                    {
-                        dbTriggerParams[tableName].Add(trigger);
-                    }
-                }
-
-            var dbContext = new EGDbContext(optionsBuilder.Options, Options.Create(dbTriggerParams));
-            dbContext.IsMigration = true;
-            return dbContext;
-        }
-    }
-}
-#endif