remove site.pubsub

It's an internal implementation detail and shouldn't be exposed.
It can be (and has been) used for cheating.

ui/round/src/ctrl.ts

@@ -160,7 +160,7 @@ export default class RoundController implements MoveRootCtrl {
   };
 
   private onUserMove = (orig: cg.Key, dest: cg.Key, meta: cg.MoveMetadata) => {
-    if (!this.keyboardMove?.usedSan) ab.move(this, meta);
+    if (!this.keyboardMove?.usedSan) ab.move(this, meta, pubsub.emit);
     if (!this.startPromotion(orig, dest, meta)) this.sendMove(orig, dest, undefined, meta);
   };
 

ui/round/types/ab.d.ts

@@ -1,5 +1,6 @@
 declare module 'ab' {
   import { MoveMetadata } from 'chessground/types';
+  import { Pubsub } from 'common/pubsub';
   function init(round: unknown): void;
-  function move(round: unknown, meta: MoveMetadata): void;
+  function move(round: unknown, meta: MoveMetadata, emit: Pubsub['emit']): void;
 }

ui/site/src/site.ts

@@ -7,10 +7,8 @@ import { unload, redirect, reload } from './reload';
 import announce from './announce';
 import { displayLocale } from 'common/i18n';
 import sound from './sound';
-import { pubsub } from 'common/pubsub';
 
 const site = window.site;
-(site as any).pubsub = pubsub; // do not declare in index.d.ts. some extensions need this here
 // site.load is initialized in layout.scala embedded script tags
 // site.manifest is fetched
 // site.info, site.debug are populated by ui/build