Release the current polling-recovery task's ownership before invoking
the fatal-error handler. The runner bounds adapter cleanup in a child
task; disconnect() cancels the tracked polling-recovery task, so
retaining the current notifier in _polling_error_task would cancel the
fatal callback before the runner can finish its reconnect-queue or
shutdown decision.
The new _handoff_polling_fatal_error() helper clears
_polling_error_task only when it is the current notifier. Other
recovery tasks remain tracked and are still cancelled and awaited
during teardown.
Covers both network retry exhaustion and polling-conflict exhaustion.
Replaces the misleading "Restarting gateway" message with "Escalating
to gateway recovery".
Fixes#68406.
1ba0e873ff