Renderer: surface allowUnderpass on RoomSettingsData + composer

Arcturus' RoomSettingsComposer appends an extra int at the end of the
payload — room.isAllowUnderpass() ? 1 : 0 — and RoomSettingsSaveEvent
optionally reads back a boolean at the end (if bytesAvailable > 0).
The renderer side never modeled this trailing field, so the client
couldn't surface or persist it.

- RoomSettingsData: add _allowUnderpass field + getter/setter +
  propagation through the .from() copy.
- RoomSettingsDataParser: read one trailing int after the moderation
  settings, guarded by 'if(wrapper.bytesAvailable)' so older servers
  that don't emit it keep parsing cleanly.
- SaveRoomSettingsComposer: optional trailing allowUnderpass arg. The
  server's optional-read guard tolerates 24-arg or 25-arg payloads, so
  callers that don't care about the field still send the legacy shape.

Cross-repo reference points:
- Arcturus emit side: Emulator/src/main/java/com/eu/habbo/messages/
  outgoing/rooms/RoomSettingsComposer.java line 55.
- Arcturus read side: Emulator/src/main/java/com/eu/habbo/messages/
  incoming/rooms/RoomSettingsSaveEvent.java lines 133-135.

Net client tsgo error count: 3 -> 0 on the NavigatorRoomSettings cluster.

packages/communication/src/messages/outgoing/room/data/SaveRoomSettingsComposer.ts

@@ -32,7 +32,8 @@ implements
         chatBubbleWeight: number,
         chatBubbleSpeed: number,
         chatDistance: number,
-        chatFloodProtection: number
+        chatFloodProtection: number,
+        allowUnderpass?: boolean
     )
     {
         //@ts-ignore
@@ -67,6 +68,8 @@ implements
             chatDistance,
             chatFloodProtection
         );
+
+        if(allowUnderpass !== undefined) this._data.push(allowUnderpass);
     }
 
     public getMessageArray()

packages/communication/src/messages/parser/roomsettings/RoomSettingsData.ts

@@ -37,6 +37,7 @@ export class RoomSettingsData
     private _roomModerationSettings: RoomModerationSettings = null;
     private _chatSettings: RoomChatSettings = null;
     private _allowNavigatorDynamicCats: boolean = false;
+    private _allowUnderpass: boolean = false;
 
     public static from(settings: RoomSettingsData)
     {
@@ -65,6 +66,7 @@ export class RoomSettingsData
         instance._roomModerationSettings = settings._roomModerationSettings;
         instance._chatSettings = settings._chatSettings;
         instance._allowNavigatorDynamicCats = settings._allowNavigatorDynamicCats;
+        instance._allowUnderpass = settings._allowUnderpass;
 
         return instance;
     }
@@ -329,4 +331,14 @@ export class RoomSettingsData
     {
         this._allowNavigatorDynamicCats = flag;
     }
+
+    public get allowUnderpass(): boolean
+    {
+        return this._allowUnderpass;
+    }
+
+    public set allowUnderpass(flag: boolean)
+    {
+        this._allowUnderpass = flag;
+    }
 }

packages/communication/src/messages/parser/roomsettings/RoomSettingsDataParser.ts

@@ -49,6 +49,10 @@ export class RoomSettingsDataParser implements IMessageParser
         this._roomSettingsData.allowNavigatorDynamicCats = wrapper.readBoolean();
         this._roomSettingsData.roomModerationSettings = new RoomModerationSettings(wrapper);
 
+        // Custom Arcturus extension: trailing int (0/1) for the underpass toggle.
+        // Older servers may not emit it; default stays false when absent.
+        if(wrapper.bytesAvailable) this._roomSettingsData.allowUnderpass = (wrapper.readInt() === 1);
+
         return true;
     }