Try detecting default game install when running patcher

src/DayZLauncher.UnixPatcher/Common.cs

@@ -22,6 +22,20 @@ public static string MoveFileToBackup(string filePath)
         return newPath;
     }
 
+    public static string? TryGetGameInstallPathFromSystem()
+    {
+        var homePath = Environment.GetEnvironmentVariable("HOME");
+        var gameInstallPath = $"{homePath}/.steam/steam/steamapps/common/DayZ";
+
+        if (Directory.Exists(gameInstallPath))
+        {
+            WriteLine($"Game data found from system: '{gameInstallPath}'");
+            return gameInstallPath;
+        }
+
+        return null;
+    }
+
     public static string? TryGetGamePrefixFromSystem()
     {
         var homePath = Environment.GetEnvironmentVariable("HOME");

src/DayZLauncher.UnixPatcher/Program.cs

@@ -4,9 +4,18 @@
 Common.WriteLine("NOTICE: This version will not enable settings saving, but mod installing should still work.", ConsoleColor.Yellow);
 Common.WriteLine("Be sure to verify game files and delete compatdata for `221100` before continuing!", ConsoleColor.Red);
 
+var gameSystemPath = Common.TryGetGameInstallPathFromSystem();
+var gameFound = !string.IsNullOrWhiteSpace(gameSystemPath);
+
 string? userInput;
-if (args is null || args.Length < 1)
+if (gameFound)
+{
+    Common.WriteLine($"Found DayZ installation at '{gameSystemPath}'");
+    userInput = gameSystemPath;
+}
+else if (args is null || args.Length < 1)
 {
+
     Common.WriteLine("");
     Common.WriteLine("Enter full DayZ installation path and press ENTER");
     Console.Write("> ");