Addressing the P1 note from the Codex reviewer: applyCustomHeaders is
also called with a synthetic &http.Request{Header: ...} from the
websockets executors (aistudio_executor.go, codex_websockets_executor.go),
which forward only the header map. The previous continue meant a custom
Host was dropped from that map, regressing virtual-host overrides on
those flows. Mirror the value to both r.Host (for real net/http) and
r.Header (for header-map-only consumers).
muzhi1991
eba561bf6f