message: broadcast disconnect
diff: @@ -23,6 +23,7 @@ import {
  DappEvents,
  UnbindEventListener,
  } from '@cardstack/web-client/utils/events';
  +import { registerDestructor } from '@ember/destroyable';
  const WALLET_CONNECT_BRIDGE = 'https://safe-walletconnect.gnosis.io/';
  @@ -53,9 +54,15 @@ export default class KovanWeb3Strategy implements Layer1Web3Strategy {
  @tracked daiBalance: BN | undefined;
  @tracked cardBalance: BN | undefined;
  #waitForAccountDeferred = defer<void>();
  + broadcastChannel: BroadcastChannel;
  constructor() {
  this.initialize();
  + this.broadcastChannel = new BroadcastChannel(this.chainName);
  + this.broadcastChannel.onmessage = (event: MessageEvent) => {
  + if (event.data === 'disconnected') this.onDisconnect();
  + };
  + registerDestructor(this, this.broadcastChannel.close);
  }
  get providerStorageKey(): string {
  @@ -139,6 +146,7 @@ export default class KovanWeb3Strategy implements Layer1Web3Strategy {
  if (this.isConnected) {
  this.clearLocalConnectionState();
  this.dappEvents.emit('disconnect');
  + this.broadcastChannel.postMessage('disconnected');
  }
  }
  