Allow silent launch via environment variable

src/XIVLauncher.Common/EnvironmentSettings.cs

@@ -10,6 +10,7 @@ public static class EnvironmentSettings
         public static bool IsNoRunas => CheckEnvBool("XL_NO_RUNAS");
         public static bool IsIgnoreSpaceRequirements => CheckEnvBool("XL_NO_SPACE_REQUIREMENTS");
         public static bool IsOpenSteamMinimal => CheckEnvBool("XL_OPEN_STEAM_MINIMAL");
+        public static bool IsSilent => CheckEnvBool("XL_SILENT");
         private static bool CheckEnvBool(string var) => bool.Parse(System.Environment.GetEnvironmentVariable(var) ?? "false");
     }
 }

src/XIVLauncher/App.xaml.cs

@@ -422,7 +422,14 @@ private void App_OnStartup(object sender, StartupEventArgs e)
                     Log.Information("Starting update check...");
 
                     _updateWindow = new UpdateLoadingDialog();
-                    _updateWindow.Show();
+                    if (!EnvironmentSettings.IsSilent)
+                    {
+                        _updateWindow.Show();
+                    }
+                    else
+                    {
+                        App.Settings.AutologinEnabled = true
+                    }
 
                     var updateMgr = new Updates();
                     updateMgr.OnUpdateCheckFinished += OnUpdateCheckFinished;