filtered null and duplicate player names in ReportCommand responses for improved reliability

common/src/main/java/eu/mhsl/craftattack/spawn/common/appliances/metaGameplay/report/ReportCommand.java

@@ -13,6 +13,7 @@ import org.jetbrains.annotations.Nullable;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
+import java.util.Objects;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
@@ -46,7 +47,7 @@ class ReportCommand extends ApplianceCommand.PlayerChecked<Report> {
             response = Stream.concat(
                 Bukkit.getOnlinePlayers().stream().map(Player::getName),
                 Arrays.stream(Bukkit.getOfflinePlayers()).map(OfflinePlayer::getName)
-            ).toList();
+            ).filter(Objects::nonNull).distinct().toList();
         }
 
         if(args.length == 2) {