enable MCU temp for ESP

docs/ARCHITECTURE.md

@@ -858,7 +858,7 @@ Repeaters and room servers default to `CONFIG_ZEPHCORE_REPEATER_GPS_INTERVAL_SEC
 - `powerOff()` (CLI `poweroff`/`shutdown`, UI power-off, low-battery shutdown all end in `zephcore_power_off()`, `board/zephyr_poweroff.c`): UI hook (heartbeat, display), GPS/sensor/buzzer rails off, LoRa held in reset, sw0 SENSE armed (nRF), power latch released, System OFF
 - Upstream's pwrmgt getters: reset cause from `boot_info`, the last fatal error from `fatal_reboot.c`'s `__noinit` record (reason, pc, lr, thread; resolve pc with `addr2line` on the same build), shutdown reason from the `/lfs/shutdn` marker, battery voltage at boot
 
-**Telemetry** (`REQ_TYPE_GET_TELEMETRY_DATA`, every role, upstream's shape): battery on channel 1, then `sensors.querySensors()` (`adapters/sensors/ZephyrSensorManager.cpp`): GPS position on channel 1 while the GPS is on and has a fix, each environment sensor and power-monitor channel found at boot on its own channel from 2 up (probe order), board-local analog sensors (T1000-E) on channel 1; then the MCU temperature on channel 1. Servers give guests battery + MCU temperature only and honour the requester's inverse permission mask, as upstream. Encoded by `helpers/compat/CayenneLPP.h`: upstream's library API and wire format, but values round to the nearest step where the library truncates.
+**Telemetry** (`REQ_TYPE_GET_TELEMETRY_DATA`, every role, upstream's shape): battery on channel 1, then `sensors.querySensors()` (`adapters/sensors/ZephyrSensorManager.cpp`): GPS position on channel 1 while the GPS is on and has a fix, each environment sensor and power-monitor channel found at boot on its own channel from 2 up (probe order), board-local analog sensors (T1000-E) on channel 1; then the MCU temperature on channel 1 (the SoC's die sensor: the `die-temp0` alias, which is `coretemp` on ESP32-S3/C3/C6, else the Nordic nodelabel `temp`; omitted where there is none: classic ESP32, STM32WL, MG24). Servers give guests battery + MCU temperature only and honour the requester's inverse permission mask, as upstream. Encoded by `helpers/compat/CayenneLPP.h`: upstream's library API and wire format, but values round to the nearest step where the library truncates.
 
 **Clock** (`adapters/clock/ZephyrRTCClock`): `setCurrentTime()` also writes the hardware RTC when the board has one (coalesced on the system work queue; a time outside 2000-2099 is not written), as upstream's `AutoDiscoverRTCClock` writes its chip; `seedCurrentTime()` is the boot restore, not written back. A chip is adopted at boot only once it is identified (`adapters/clock/ZephyrRTCDiscover.c`), because other parts can answer at the same address: a device is passed over when two reads each show a bit set that the chip's data sheet fixes at zero, or a time field out of range, and a time is restored only from a read in which every field is valid. An RV-3028 cleanly identified in 12-hour mode has its `twelve-hour-bit` cleared first, so the chip converts its own hours. No time is taken from a cleanly identified RV-3028 whose `twelve-hour-bit` register cannot be read or reads FFh, or whose clear or re-read fails. The time is written in each chip's own encoding (the RX8130CE takes a one-hot weekday, `weekday-one-hot` in its descriptor), and an RV-3028 whose descriptor carries `rv3028-eeprom-config` (the RAK12002 on a RAK4631) has that configuration, its backup switchover, stored in the chip's EEPROM. Without a hardware RTC, the last time read is kept in no-init memory (RTC slow memory on ESP32) and restored after a reset that keeps RAM (reboot, crash, watchdog), as upstream's `ESP32RTCClock`; a power cycle starts from 1970 again.