feat: populate MyNodeInfo.device_id on all platforms (#10995)

* feat: populate MyNodeInfo.device_id on all platforms

RP2040/RP2350 use the 64-bit pico unique board id, STM32WL the 96-bit
silicon UID, ESP32-S2 joins the existing OPTIONAL_UNIQUE_ID efuse branch,
and everything else (classic ESP32 in particular) falls back to a
deterministic factory-MAC-derived id, resolving the long-standing FIXME.
Portduino keeps the config-supplied id preferred and now uses the MAC
fallback when the config omits one.

No proto or persistence changes; the id is re-read from silicon each
boot and PhoneAPI still zeroes it for unauthenticated clients.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* fix: declare zero_mac const to satisfy cppcheck

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* fix: address review feedback on device_id derivation

Clear any disk-loaded device_id before the silicon derivation so a failed
read leaves it unset rather than stale (Copilot), and size the portduino
config copy with sizeof instead of a literal 16 (CodeRabbit).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* refactor: extract device_id generation into per-arch getDeviceId()

Per review feedback on #10995: move the platform-specific
MyNodeInfo.device_id derivation out of the #if/#elif ladder in
NodeDB.cpp into a getDeviceId() interface (target_specific.h)
implemented per-architecture alongside each platform's getMacAddr():

  - esp32:     efuse OPTIONAL_UNIQUE_ID (C3/S2/S3/C6); classic ESP32 -> MAC
  - nrf52:     FICR DEVICEID + DEVICEADDR
  - nrf54l15:  FICR->INFO.DEVICEID + DEVICEADDR (NRF_FICR-guarded, MAC fallback)
  - rp2xx0:    pico_get_unique_board_id()
  - stm32wl:   HAL_GetUIDw0/1/2()
  - portduino: config-supplied id preferred, else MAC

The shared MAC-derived fallback moves to meshUtils as
getMacAddrDeviceId(). NodeDB.cpp now zero-inits the field and makes a
single getDeviceId() call, dropping ~65 lines of platform boilerplate
plus the esp_efuse/pico/stm32 includes that came with it. No behavior
change: device_id is still re-read from silicon each boot and never
persisted.

Builds green: native-macos, tbeam, heltec-v3, rak4631, rak11310, rak3172.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

* fix: address review of device_id refactor

- getMacAddrDeviceId(): zero-init the mac[6] buffer. getMacAddr() can return
  without writing (e.g. Portduino with no MAC source), so the old uninitialized
  buffer let stack garbage pass the all-zeros guard and become device_id. The
  pre-refactor code relied on the zero-initialized static ourMacAddr; restore
  that guarantee.
- nrf54l15 getDeviceId(): drop the `#if defined(NRF_FICR)` guard and read FICR
  unconditionally (as the pre-refactor NodeDB code did). The guarded #else fell
  back to getMacAddr()'s hard-coded placeholder MAC, which would give every unit
  an identical device_id; a missing NRF_FICR should be a loud compile error.
- NodeDB.cpp: `#include "target_specific.h"` instead of hand-copied externs for
  getMacAddr/getDeviceId; retire the stale FIXME. Same for meshUtils.cpp (whose
  extern comment wrongly claimed the TU was Arduino-free).
- Delete the orphaned commented-out device_id hex-dump block in NodeDB.cpp.
- Trim/de-duplicate the getDeviceId contract comments (single-sourced in
  target_specific.h).

Builds green: native-macos, tbeam.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

* docs: trim device_id comments to the repo's 1-2 line guideline

Addresses CodeRabbit review nitpick on #10995: shorten the getDeviceId()
(target_specific.h), getMacAddrDeviceId() (meshUtils.h), device-id refresh
(NodeDB.cpp), and nrf54l15 getDeviceId comments to two lines each, per the
"one or two lines maximum" coding guideline. Comment-only; no behavior change.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

---------

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

src/platform/nrf52/main-nrf52.cpp

@@ -186,6 +186,17 @@ void getMacAddr(uint8_t *dmac)
     dmac[0] = src[5] | 0xc0; // MSB high two bits get set elsewhere in the bluetooth stack
 }
 
+bool getDeviceId(uint8_t *deviceId)
+{
+    // Nordic burns a FIPS-compliant random id into each chip at the factory. We concatenate
+    // the device address to that random id to form the 16-byte hardware identifier.
+    uint64_t device_id_start = ((uint64_t)NRF_FICR->DEVICEID[1] << 32) | NRF_FICR->DEVICEID[0];
+    uint64_t device_id_end = ((uint64_t)NRF_FICR->DEVICEADDR[1] << 32) | NRF_FICR->DEVICEADDR[0];
+    memcpy(deviceId, &device_id_start, sizeof(device_id_start));
+    memcpy(deviceId + sizeof(device_id_start), &device_id_end, sizeof(device_id_end));
+    return true;
+}
+
 #if !MESHTASTIC_EXCLUDE_BLUETOOTH
 void setBluetoothEnable(bool enable)
 {