Add WS heartbeat every 30s to keep connection alive

src/lib/ws.ts

@@ -9,6 +9,7 @@ class WSClient {
   private ws: WebSocket | null = null;
   private handlers: Map<string, Set<MessageHandler>> = new Map();
   private reconnectTimer: ReturnType<typeof setTimeout> | null = null;
+  private heartbeatTimer: ReturnType<typeof setInterval> | null = null;
   private pendingQueue: any[] = [];
   private authenticated = false;
   private _lobbyId: string | null = null;
@@ -38,7 +39,7 @@ class WSClient {
         const msg = JSON.parse(event.data);
         const type = msg.type;
 
-        // Handle auth.ok — flush pending queue
+        // Handle auth.ok — flush pending queue + start heartbeat
         if (type === "auth.ok") {
           this._lobbyId = msg.data?.lobby_chat_id || null;
           this._projects = msg.data?.projects || [];
@@ -49,6 +50,8 @@ class WSClient {
             this.ws!.send(JSON.stringify(queued));
           }
           this.pendingQueue = [];
+          // Start heartbeat every 30s to keep connection alive
+          this.startHeartbeat();
         }
 
         // Auth error → force re-login
@@ -73,6 +76,7 @@ class WSClient {
 
     this.ws.onclose = () => {
       this.authenticated = false;
+      this.stopHeartbeat();
       this.reconnectTimer = setTimeout(() => this.connect(), 3000);
     };
 
@@ -81,12 +85,27 @@ class WSClient {
 
   disconnect() {
     if (this.reconnectTimer) clearTimeout(this.reconnectTimer);
+    this.stopHeartbeat();
     this.ws?.close();
     this.ws = null;
     this.authenticated = false;
     this.pendingQueue = [];
   }
 
+  private startHeartbeat() {
+    this.stopHeartbeat();
+    this.heartbeatTimer = setInterval(() => {
+      this.heartbeat();
+    }, 30_000);
+  }
+
+  private stopHeartbeat() {
+    if (this.heartbeatTimer) {
+      clearInterval(this.heartbeatTimer);
+      this.heartbeatTimer = null;
+    }
+  }
+
   on(type: string, handler: MessageHandler) {
     if (!this.handlers.has(type)) this.handlers.set(type, new Set());
     this.handlers.get(type)!.add(handler);