fix(auth): C2 review — not-found throws (no spurious audit) on update/delete/set-methods, reject empty methods (unusable-key/stealth-disable), richer set-methods response, token advisory to stderr

src/ZB.MOM.WW.ScadaBridge.CLI/Commands/SecurityCommands.cs

@@ -122,9 +122,10 @@ public static class SecurityCommands
     /// <summary>
     /// Renders the create-key response, surfacing the one-time bearer token prominently —
     /// it is the only moment the secret is available and cannot be retrieved afterwards.
+    /// The advisory line is written to stderr so that piping stdout captures only the token.
     /// </summary>
     /// <param name="json">The JSON success body returned by the management API.</param>
-    private static int PrintCreatedKey(string json)
+    internal static int PrintCreatedKey(string json)
     {
         using var doc = System.Text.Json.JsonDocument.Parse(json);
         var root = doc.RootElement;
@@ -133,7 +134,7 @@ public static class SecurityCommands
 
         Console.WriteLine($"API key created. KeyId: {keyId}");
         Console.WriteLine();
-        Console.WriteLine("Save this token now — it will not be shown again:");
+        Console.Error.WriteLine("Save this token now — it will not be shown again:");
         Console.WriteLine($"  {token}");
         return 0;
     }