fix(cli): exit 0 on --help, handle parse errors cleanly

--help printed usage but returned exit code 1, failing the CI smoke test. Treat --help / -h / no-args as a successful usage print (exit 0), and catch parser ArgumentExceptions so a missing value or bad --mode exits 1 with a message instead of an unhandled crash.

cli/DorkNet.ServerCli/Program.cs

@@ -14,8 +14,15 @@ public static class Program
 {
     public static async Task<int> Main(string[] args)
     {
+        // --help / -h (and a bare invocation) print usage and exit cleanly.
+        if (args.Length == 0 || args.Contains("--help") || args.Contains("-h"))
+        {
+            PrintHelp();
+            return 0;
+        }
+
         var parsed = ParseArgs(args);
-        if (parsed is null) return 1; // ParseArgs already wrote --help or an error.
+        if (parsed is null) return 1; // ParseArgs already wrote the error.
 
         // Validate required values up front so the user sees the
         // failure before any download / process spin-up.
@@ -216,17 +223,13 @@ public static class Program
 
     private static ParsedArgs? ParseArgs(string[] args)
     {
-        if (args.Length == 0 || args.Contains("--help") || args.Contains("-h"))
-        {
-            PrintHelp();
-            return null;
-        }
-
         string photon = "", voice = "", region = "us";
         string mode = "localtunnel", apex = "", name = "DorkNet Server";
         string versionKey = "march_2020_03_10";
         string? serverDir = null;
 
+        try
+        {
             for (int i = 0; i < args.Length; i++)
             {
                 string Next()
@@ -261,6 +264,12 @@ public static class Program
 
             return new ParsedArgs(photon, voice, region, parsedMode, apex, name, versionKey, serverDir);
         }
+        catch (ArgumentException ex)
+        {
+            Console.Error.WriteLine($"error: {ex.Message} (try --help)");
+            return null;
+        }
+    }
 
     private static void PrintHelp()
     {