Add tryout command for TUI onboarding

Add a new /tryout command as an extensible entry point for recommended feature trials, with /tryout tui as the first action. The command updates [Console.General] ConsoleMode to "tui", writes the config back immediately, and explains both how to revert the change and that a restart is required.

Also show a startup recommendation in classic console mode when stdin is interactive, so users can discover the TUI experience without manually editing MinecraftClient.ini. All user-facing text is routed through the translation resources.

MinecraftClient/Program.cs

@@ -193,6 +193,7 @@ namespace MinecraftClient
             if (!ProcessStartupState(startupState))
                 return;
 
+            MaybePrintClassicModeTuiRecommendation();
             RunStartupSequence(args);
         }
 
@@ -247,6 +248,19 @@ namespace MinecraftClient
             return true;
         }
 
+        private static void MaybePrintClassicModeTuiRecommendation()
+        {
+            if (ConsoleIO.BasicIO
+                || Config.Console.General.ConsoleMode != ConsoleModeType.classic
+                || Console.IsInputRedirected)
+            {
+                return;
+            }
+
+            char cmdChar = Config.Main.Advanced.InternalCmdChar.ToChar();
+            ConsoleIO.WriteLineFormatted("§8" + string.Format(Translations.mcc_console_mode_tui_recommendation, cmdChar));
+        }
+
         /// <summary>
         /// Handles a failed config load by prompting the user to fix or regenerate the config file.
         /// </summary>