> so basically the ideal solution here would be to deploy a simple Hetzner app (caddy/nginx or the hosted options hetzner has), set up a cheap CDN (Bunny, Cloudflare, etc) in front of it

I agree! Cloudflare probably won't be this cheap forever but like I said I think that's the optimal solution, with the option to cut over and take the latency penalty if costs are out of control.