Same gap as the screens had: the bot reply, a typed message's {temp} and
the placeholder lists read only the sensors, so a board without one (the
L1) answered !temp with n/a while its telemetry carried a temperature.
The fallback moves to LocalSensors.h, shared by the screens, expandMsg()
and sensorPlaceholders(); the latter now takes the chip's temperature.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>