detect pong for unified ws

src/util/requestUtils.ts

@@ -73,6 +73,10 @@ export function isWsPong(msg: any): boolean {
     return true;
   }
 
+  if (msg['ret_msg'] === 'pong') {
+    return true;
+  }
+
   return (
     msg.request &&
     msg.request.op === 'ping' &&

src/util/websocket-util.ts

@@ -153,6 +153,9 @@ export const PUBLIC_WS_KEYS = [
   WS_KEY_MAP.spotV3Public,
   WS_KEY_MAP.usdcOptionPublic,
   WS_KEY_MAP.usdcPerpPublic,
+  WS_KEY_MAP.unifiedOptionPublic,
+  WS_KEY_MAP.unifiedPerpUSDTPublic,
+  WS_KEY_MAP.unifiedPerpUSDCPublic,
 ] as string[];
 
 /** Used to automatically determine if a sub request should be to the public or private ws (when there's two) */