Add ServerState support in ChatService with SSE listener and associated data model

frontend/src/app/pages/altitude/chat/objects/server-state.object.ts

@@ -0,0 +1,14 @@
+export interface User {
+  uuid: string;
+  name: string;
+  styledName: string;
+}
+
+export interface Server {
+  name: string;
+  players: User[];
+}
+
+export interface ServerState {
+  servers: Server[];
+}

frontend/src/app/pages/altitude/chat/service/chat.service.ts

@@ -8,6 +8,7 @@ import {precomputeNode} from '@pages/altitude/chat/mini-message/mini-message.uti
 import {ChatChannel} from '@pages/altitude/chat/objects/chat-channel.object';
 import {NotificationService} from '@pages/altitude/chat/service/chat-notification.service';
 import {ChatInfoService} from '@api';
+import {ServerState} from '@pages/altitude/chat/objects/server-state.object';
 
 interface SsePayloadEvent {
   data: string;
@@ -24,6 +25,8 @@ export class ChatService implements OnDestroy {
   public readonly channels = computed(() => this._channels().sort((a, b) => a.name.localeCompare(b.name)));
   private readonly _selectedChannel = signal<ChatChannel | null>(null);
   public readonly selectedChannel = this._selectedChannel.asReadonly()
+  private readonly _serverState = signal<ServerState | null>(null);
+  public readonly serverState = this._serverState.asReadonly();
   public readonly partieMap = signal<Map<string, string>>(new Map());
   public readonly userNameMap = signal<Map<string, string>>(new Map());
   private readonly pendingPartyNameRequests = new Set<string>();
@@ -78,6 +81,11 @@ export class ChatService implements OnDestroy {
         });
     });
 
+    this.on(source, 'server-state', (event) => {
+      const state = JSON.parse(event.data) as ServerState;
+      this._serverState.set(state);
+    });
+
     source.onerror = (err) => {
       console.error('SSE error, polyfill will auto-reconnect:', err);
     };