add cache headers to the network stats response so theyre cached by browsers briefly

[gruns]

add a short cache ttl, my gut says around 10s to 30s, to the network stats response (the response from https://uc2x7t32m6qmbscsljxoauwoae0yeipw.lambda-url.us-west-2.on.aws/?...)

this

1. lets this response be cached by a CDN to protect the db behind the response
2. loads the stats instantly (and prevents an extra, unnecessary network requests from being made) on a quick tab refresh after initial page load

this isnt much work but is low priority