aww, thanks :)
BTW for anyone reading, https://wormhole.app/ is awesome and serves a very similar purpose, but uses entirely different technology (no PAKE) and has a different security model.
In my (https://magic-wormhole.io) world, we've kicked around ways to make a good browser-based client (and I've tried to prepare the protocols to work well there), but I haven't had time to pursue any of them. The tasks include 1: port everything to JS (or take the core of the Rust port and compile it to WASM, then write an IO layer in JS), 2: glue it to the browser's file/blob upload/download APIs, 3: settle on a trusted-application security model.
To make it work in a vanilla browser with no setup phase, you're pretty much limited to relying upon the webserver from which you get the page, which is the model wormhole.app provides. Other options include using an addon (which shifts the reliance set slightly), or running some sort of Electron thing (making it not really a browser app) that you get from some distribution channel (debian, homebrew, etc) which shifts the reliance set in a better direction.. at least you're probably getting the same application as everybody else using that distribution, vs a webserver that could conceivably serve up a different version each time.