fix typescript error en GameRoom

Reemplaza getAvailableData() que no existe en la clase Room de Colyseus
con getFilterOptions() y implementación manual.

server/src/rooms/GameRoom.ts

@@ -7,7 +7,7 @@ import { broadcastDashboardUpdate } from "../adminApi";
 export class GameRoom extends Room<GameState> {
   maxClients = 2;
 
-  getAvailableData() {
+  getFilterOptions() {
     // If waiting for shuffled players, report as available regardless of current client count
     if (this.isWaitingForShuffledPlayers) {
       return {
@@ -16,7 +16,11 @@ export class GameRoom extends Room<GameState> {
         metadata: this.metadata
       };
     }
-    return super.getAvailableData();
+    return {
+      clients: this.clients.length,
+      maxClients: this.maxClients,
+      metadata: this.metadata
+    };
   }
 
   hasReachedMaxClients() {