Live staging (2026-08-01): relay semantic thread rename still declined
silently despite both #74482 and #75581 deployed — thread kept its
initial-words name, session title generated fine. Root cause is the
no-clobber guard string mismatch (see paired gateway-gateway PR): the
gateway can't reproduce the thread's initial name byte-for-byte, so the
connector's only_if_current_name check always failed.
- relay rename lane now passes prefer_connector_created=True instead of
the fragile initial-name string; the connector resolves the guard from
its own created-name memory. Native-marker lane keeps the legacy
only_if_current_name string (source carries the real initial name).
- rename_thread: prefer_connector_created param -> only_if_connector_created
on the wire, precedence over the legacy string.
- INFO logs at rename dispatch (thread/lane/new_title) and result
(applied=bool): the whole failure hunt needed telemetry the gateway
never emitted — this makes the outcome visible in fly logs.
Tests: connector-guard wire shape + precedence over legacy string; the
title-turn race test updated to assert the connector-owned guard. Relay
suite 149 passed; ruff + footguns clean.