installFetchInterceptor local bypass

installFetchInterceptor() must never intercept config.gatewayBase or local hosts (localhost, 127.0.0.1, 0.0.0.0, ::1, [::1]). Broad interception looks consistent but can recurse into Lore or hijack a local LLM. Gateway-bound requests must still call observeRequestHeaders() for side-channel scoping, then use originalFetch(input, init).