Add logging for server subscriptions in ServerMessageService

backend/src/main/java/com/alttd/altitudeweb/services/chat/to_server/ServerMessageService.java

@@ -27,6 +27,7 @@ public class ServerMessageService {
 
     public synchronized SseEmitter subscribe(String server) {
         servers.add(server);
+        log.info("Server {} subscribed", server);
         SseEmitter emitter = eventPublisher.subscribe(server, this::handleSessionEnd);
         if (latestPlayerState != null) {
             eventPublisher.sendToUser(server, PLAYER_STATE_CHANNEL, latestPlayerState);

frontend/src/app/pages/altitude/chat/components/user-list/user-list.component.ts

@@ -18,7 +18,9 @@ export class UserListComponent {
 
   protected readonly serverState = computed(() => {
     const state = this.chatService.serverState();
-    if (!state) return null;
+    if (!state) {
+      return null;
+    }
 
     return {
       servers: [...state.servers]