This doesn't do a good job maintaining state across morphs, but hey
it's Working At All in terms of wiring, and that's good!!
Also need to style up the toggle as a cute button instead of a visible
checkbox and the words "Play/pause"!
Not using this on the item page preview yet, but we will!
I like this approach over e.g. a web component specifically for the
sandboxing: while I don't exactly *distrust* JS that we're loading from
Neopets.com, I don't like the idea of *any* part of the site that
executes arbitrary JS unsafely at runtime, even if we theoretically
trust where it theoretically came from. I don't want any failure
upstream to have effects on us!
I copied basically all of the JS from a related project
`impress-media-server` that I had spun up at one point, to investigate
similar embed techniques. Easy peasy drop-in-squeezy!
