No indicator that the WASM module is still loading

[HeCorr]

Today when attempting to use the tool, I noticed that clicking Generate Keys did nothing, and when checking the console, it showed the error generateX25519Identity is not defined.

After further investigation, I noticed that the age.wasm module was taking a few seconds to finish downloading (it's 871 kB, just for reference).

I believe it would be helpful to make it clear that the module hasn't been loaded yet by preventing the user from clicking anything, and/or maybe showing a temporary loading text.

[HeCorr]

There's also a bug where clicking Generate Keys redirects to /?privkey=&pubkey= which may or may not be related to this.

I'm actually a bit confused on that one, because e.preventDefault() is the first thing that gets called when clicking the buttons, so that means that main.js is somehow getting delayed...? not sure. more investigation is required.