Adds TestGostTargetPolicyBypass: a service-level bypass blacklists the
echo server; verifies the control request is 403, a checksum-valid
Gost-Target header naming an allowed authority cannot reach the blocked
backend, and a malformed header is fail-closed. Verified to catch the bug
by reverting the fix (exploit returned the backend response).
Adds 12 new HTTP handler test scenarios: HTTP connector (no-auth, auth, TLS
upstream), CONNECT tunnel (no-sniffing, bypass-403), probeResist (host, web,
file, knock), idleTimeout, and UDP relay over HTTP. Introduces
RunGostContainerWithFiles helper for mounting extra files into test containers.
ginuerzh