chore(Finalizer.Program): enhance configuration and environment-specific JSON loading

- Changed Serilog configuration file from `appsettings.json` to `appsettings.Logging.json`.
- Added logging for application startup.
- Dynamically load environment-specific appsettings JSON files, excluding `Development` and `migration` files.

EnvelopeGenerator.Finalizer/Program.cs

@@ -7,12 +7,14 @@ using Serilog;
 // Load Serilog from appsettings.json
 Log.Logger = new LoggerConfiguration()
     .ReadFrom.Configuration(new ConfigurationBuilder()
-        .AddJsonFile("appsettings.json", optional: false, reloadOnChange: true)
+        .AddJsonFile("appsettings.Logging.json", optional: false, reloadOnChange: true)
         .Build())
         .CreateLogger();
 
 try
 {
+    Log.Information("Application is starting...");
+
     var builder = Host.CreateApplicationBuilder(args);
 
     // add serilog
@@ -20,6 +22,14 @@ try
     builder.Logging.AddSerilog();
 
     var config = builder.Configuration;
+
+    Directory
+        .GetFiles(builder.Environment.ContentRootPath, "appsettings.*.json", SearchOption.TopDirectoryOnly)
+        .Where(file => Path.GetFileName(file) != $"appsettings.Development.json")
+        .Where(file => Path.GetFileName(file) != $"appsettings.migration.json")
+        .ToList()
+        .ForEach(file => config.AddJsonFile(file, true, true));
+
     builder.Services.AddHostedService<Worker>();
 
     #region Add DB Context, EG Inf. and Services