Reproduce the regression where a domain-only whitelist bypass on a red
(transparent) proxy rejected every connection: the pre-sniffing bypass
check ran against the bare destination IP, which is never in a domain
whitelist, before SNI sniffing could match. A privileged container
redirects outbound TCP to the red service; asserts an allowlisted SNI
is forwarded (hello-gost) and a non-allowlisted SNI is rejected.
