fix(ui): the chip's temperature when no sensor reads one

The telemetry reply adds the MCU temperature, the screens read only the
sensors: on a board without a temperature sensor (the L1) the app showed
a temperature and the clock field '--'. The clock, Status and the L2's
Home now fall back to the chip's, like the reply. The bot's !temp and
{temp} still read only the sensors.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

examples/companion_radio/ui-lvgl/HomeScreen.h

@@ -621,7 +621,7 @@ void UITask::homeFieldText(uint8_t f, char* v, int n) {
     if (_sensors && (s_lpp_ms == 0 || millis() - s_lpp_ms > 5000)) {
       s_lpp_ms = millis() | 1;
       s_lpp.reset();
-      _sensors->querySensors(0xFF, s_lpp);
+      telemetry::querySensors(*_sensors, board.getMCUTemperature(), s_lpp);
     }
     in.lpp = s_lpp.getBuffer();
     in.lpp_len = s_lpp.getSize();