Launcher can be minimized to a small bar in the start menu

A '-' button collapses the fullscreen launcher into a small MSCO bar at the
top; the game's start menu is visible and clickable again and its music is
unmuted. Clicking the bar opens the launcher; prompts (disconnected,
reconnecting, join confirmation, version warning) open it automatically.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

MenuHelper.cs

@@ -84,11 +84,21 @@ namespace MSCO
                 var src = (AudioSource)o;
                 if (src == null || src.mute || src.transform.root.name.StartsWith("MSCO")) continue;
                 src.mute = true;
+                mutedByUs.Add(src);
                 muted++;
             }
             return muted;
         }
 
+        static readonly System.Collections.Generic.List<AudioSource> mutedByUs = new System.Collections.Generic.List<AudioSource>();
+
+        /// <summary>Launcher eingeklappt: die von uns stummgeschalteten Menü-Geräusche wieder an.</summary>
+        public static void UnmuteMenuAudio()
+        {
+            foreach (AudioSource src in mutedByUs) if (src != null) src.mute = false;
+            mutedByUs.Clear();
+        }
+
         public static void StartGame()
         {
             PlayMakerFSM fsm;