Load layouts and optional features from staged asset caches

frontend/p2p-recv-worker.js

@@ -12,7 +12,6 @@
  * The ".part" suffix keeps OPFS.listVideos() from ever listing a partial file.
  * ========================================================================== */
 'use strict';
-importScripts('/sha256.js');
 
 let dir = null;
 let handle = null;
@@ -36,6 +35,7 @@ self.onmessage = (e) => { chain = chain.then(() => onOp(e.data || {})); };
 
 async function onOp(m) {
   try {
+    if (!self.Sha256) { self.__ASSET_URLS__=m.assetUrls || {}; importScripts(self.__ASSET_URLS__.sha256 || '/sha256.js'); }
     if (m.op === 'open') {
       const root = await navigator.storage.getDirectory();
       dir = await root.getDirectoryHandle('videos', { create: true });