[vitejose]

My main criterion is being able to use existing software since I can’t have folks install anything that’s not approved. This brings me to the web browser, which, for better or worse, has become the ultimate application distribution platform. I suppose it’s not strictly necessary that the programs be delivered as a single file but given that I probably won’t be able to properly host them, I figure it’s easiest to just have a self-contained .html file that can exist on the NAS or be sent via email.

I’m not trying to build anything huge; mostly just a few utilities with some buttons and text input forms that spit out XML files, for instance.

[solardev]

You can get free hosting at Vercel or Netlify or similar. There's no reason to do what you want as a single file. Just write normal HTML and Javascript.

Being able to send people a URL is a lot easier than having to mail them a huge HTML file with everything embedded, even if you could theoretically do that with like data URLs and base 64 encoded images and whatnot. It's just not necessary and will make your project more complicated. And updates will be very hard to manage.

There's a whole industry built around web apps because they are easy to deliver to anyone with a browser. You don't have to reinvent the wheel here.