feat: response body dataURLs

Author: Sebastien Ringrose

Store.ts

@@ -1,7 +1,5 @@
 import { serialize, parseFcnString } from "./utils.ts"
 
-const encoder = new TextEncoder()
-
 interface Shelf {
   get: (nodeId:string) => Promise<string> | Promise<undefined> | string | undefined,
   set: (nodeId:string, nodeStr: string) => Promise<string> | Promise<void> | string | void,